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Zinc oxide (ZnO) has garnered significant attention in photovoltaic research due to its exceptional optical and electronic properties, which complement traditional silicon (Si) solar cells. This work investigates the characteristics of integrating nanostructured ZnO layers over silicon substrates to enhance the performance of silicon solar cells. It also discusses the fabrication techniques for depositing ZnO on silicon, such as sol-gel method and highlights the performance of Zno with various analysis. Additionally, the potential of ZnO/Si hetero junctions in reducing recombination losses and enhancing the open-circuit voltage and short-circuit current in solar cells have been discussed. The findings suggest that the integration of ZnO into silicon solar cells paves the way for more cost-effective and scalable photovoltaic solutions. [ABSTRACT FROM AUTHOR]

On a sunny day, the front side of the bifacial solar cells is illuminated with direct and the rear side with the diffused light. Therefore, it is important to study the effect of diffusion and direct light on the bifacial solar cell. In this study, the effects of diffuse and direct light and temperature on the textured bifacial solar cell were determined by simulation. According to the obtained results, the optimal value of the angle of base of texture for a bifacial silicon solar cell is 580. On a cloudy day, under diffuse light illumination on both sides, the planar and optimally textured solar cells have an efficiency of 13.14% and 16.03% and a short-circuit current of 4.34 mA/cm² and 5.49 mA/cm². The short-circuit current is 2.28 mA/cm² and 2.88 mA/cm2 when only front side is illuminated with diffuse light. On a sunny day, when direct light falls on the front side and diffuse light falls on the rear side, the short-circuit current of the planar and optimally textured solar cell are 27.79 mA/cm² and 35.16 mA/cm², respectively. Short-circuit current are 25.73 mA/cm2 and 32.65 mA/cm² when only front side illuminated with direct light. [ABSTRACT FROM AUTHOR]

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In this work, a matchbox-sized dust detector with a wide measurement range was developed for the lunar surface applications. The characteristics of the detector response to lunar dust simulant deposition mass, particle size, light incidence angle, and temperature are investigated experimentally. It is found that in current study the short-circuit current of the dust detector decreases with the increase in dust deposition mass overall. However, the pattern of current reduction is closely dependent on the size of the dust particles. Specifically, for the dust particle in the range of 75–100 μm, the short-circuit current of the detector tends to decrease slowly and approximately linearly as the dust deposition mass increases, irrespective of light incidence angle. However, for the particle in the size range of 0–25 μm, the decrease of short-circuit current with dust deposition mass can be well described by an exponential function. In addition, the occlusion coefficients for different particle size distributions at different light incidence angles, ranging from −0.88 to −0.08, are also obtained, which is important for determining the mass range of dust deposited on lunar surface-mounted detector at the corresponding conditions. The present research can provide guidance for lunar dust detection with solar cell-based detector. • A lunar dust detector based on mono-crystalline silicon solar cell was developed. • The effect of lunar dust stimulant deposition on the detector was investigated. • The occlusion coefficient under different conditions was determined. [ABSTRACT FROM AUTHOR]

Increasing wideband absorption in crystalline silicon (c-Si) solar cells is a task that is vital in order to improve the power conversion efficiency of the device. The low light absorption of incident photons is discovered in this type of solar cell due to the bulk c-Si indirect band gap as well as low absorption coefficient characteristics. This work reports on the micro-texture size influence towards enhancing wide/broadband light absorption in hybrid microtextured/nanotextured c-Si for solar cell applications. Sodium hydroxide (NaOH) solution is used to fabricate a Microscale pyramid on c-Si. The NaOH etching is performed at different durations between 25-40 min. The one step silver-assisted wet chemical etching (one-step AgNO3-based MACE) method is applied to prepare nanowires on the pyramid. After 30 min of etching, a range of pyramids with heights between 3-7 µm and 3-10 µm of widths are formed. After the one-step AgNO3-based MACE, nanowires with 300-800 nm heights and 40-50 nm widths are obtained on the pyramids. After the fabrication of nanowires on the pyramids, considerable suppressed weighted average reflection (WAR) is obtained in all the samples, due to improved light trapping and augmented light scattering by the nanowires and the base pyramids respectively. Lowest broadband reflection (9.0 % WAR), is obtained after 30 min of etching and 80 s one-step AgNO3-based MACE. This translates to 38.9 mA/cm² maximum short-circuit current density (maximum Jsc), or 14.1% improvement compared to the maximum Jsc of the pyramids without nanowires (34.1 mA/cm²). The findings indicated that the hybrid textured surface in c-Si is a promising approach to enhance wideband light absorption and potential photocurrent for application in photovoltaic devices. [ABSTRACT FROM AUTHOR]

This experimental study investigates the damage effects of nanosecond pulse laser irradiation on silicon solar cells. It encompasses the analysis of transient pulse signal waveform characteristics at the cells' output and changes in electrical parameters, such as I–V curves before and after laser irradiation under varying laser fluence and background light intensities, and explores the underlying action mechanisms of laser irradiation. The study reveals that as the laser fluence increases up to 4.0 J/cm2, the peak value of the transient pulse signal increases by 47.5%, while the pulse width augments by 88.2% compared to the initial transient pulse signal. Furthermore, certain parameters, such as open-circuit voltage, short-circuit current, and peak power obtained, from the measured I–V curve indicate a threshold laser fluence for functional degradation of the solar cell at approximately 1.18 ± 0.42 J/cm2. Results obtained from laser irradiation under different background light intensities underscore the significant influence of background light on laser irradiation of silicon cells, with the most severe damage occurring in the absence of light. Moreover, findings from laser irradiation at multiple locations on the silicon cell demonstrate a linear decrease in the output voltage of the silicon cell with an increase in the number of irradiation points. [ABSTRACT FROM AUTHOR]

Potential‐induced degradation (PID) may be a serious concern in photovoltaic (PV) modules and plants, particularly when approaching high system voltages (1500+ V). Here, we investigate PID occurring in bifacial rear‐emitter silicon heterojunction (SHJ) solar cells encapsulated in a glass/glass (G/G) module configuration with ethylene vinyl acetate (EVA) as an encapsulant. PID testing was performed at 85°C in 85% relative humidity (RH), and the solar cells were subjected to −1 kV and +1 kV for up to 800 h. SHJ cells were found to degrade when subjected to −1 kV, and to a lesser extent when left unbiased in damp heat (DH) conditions, while the application of +1 kV prevented degradation. Although prone to PID after extended test durations, the SHJ mini‐modules investigated in this study noticeably passed the industry standard (IEC 61215:2021) PID test of 96 h. The degradation was primarily characterized by losses in short‐circuit current (ISC) at the front side, followed by fill factor (FF) and open‐circuit voltage (VOC). A cross‐sectional transmission electronic microscopy analysis of the laminates subjected to −1 kV highlighted a transport of sodium (Na) through the transparent conductive oxide (TCO), reaching the amorphous Si/TCO interface. The samples tested in DH conditions and with positive PID test conditions did not exhibit such a migration of Na. To account for these observations, we updated a previously proposed model describing the sensitivity of SHJ cells to water. In our degradation model, moisture in the module corrodes the glass, creating sodium hydroxide (NaOH) that then percolate through the EVA before reaching the SHJ cell. The application of a high negative bias amplifies the previous mechanism by increasing the availability of Na+ and also enhances the drift of Na+ through the EVA to the cell. Finally, we demonstrate that PID can be mitigated or suppressed at the module level by using a high‐volume resistivity encapsulant with a low water vapor transmission rate (WVTR) or by encapsulating SHJ solar cells in a configuration impermeable to water (e.g., using an edge sealant). [ABSTRACT FROM AUTHOR]

Improving power conversion efficiency (PCE) in photovoltaics has driven innovative approaches in solar cell design and technology. Silicon heterojunction (SHJ) solar cells exhibit advantages in PCE due to their effective passivating contact structures. SHJ–interdigitated back contact (SHJ–IBC) solar cells have the potential to surpass traditional SHJ cells, attributed to their advantage in short‐circuit current (JSC). Herein, Silvaco Atlas technology computer‐aided design is used to create digital twins of high‐efficiency SHJ solar cells with amorphous silicon and nanocrystalline silicon hole selective contact (HSC) layers. Using parameters from digital twins of SHJ solar cells, the practical efficiency limit of SHJ–IBC solar cells is assessed. The results show that SHJ–IBC cells can achieve potential efficiencies of 27.01% with amorphous HSC and 27.38% with nanocrystalline HSC. Further efficiency augmentation to 27.51% can be achieved by narrowing the gap from 80 to 20 μm. This study not only advances comprehension of SHJ–IBC solar cells but also provides insights into optimizing geometrical configurations for improved performance. The utilization of digital twins provides a valuable tool for predicting and evaluating the performance of SHJ–IBC solar cells, contributing substantively to the ongoing development of high‐efficiency photovoltaic technology. [ABSTRACT FROM AUTHOR]

Perovskite‐based triple‐junction solar cells offer the potential for highly efficient and cost‐effective photovoltaic energy conversion. This article aims to provide a roadmap for the optical properties of perovskite/perovskite/silicon triple‐junction cells. A comprehensive optoelectrical model for the perovskite/perovskite/silicon structure is developed in Sentaurus TCAD. The optical part of the model is validated by measurements of a triple‐junction solar cell. As the electrical characterization is an ongoing process, the electrical properties are assumed to be nonlimiting, which enables us to translate the optical improvement steps into efficiency potentials. A first improvement step lies in adjusting the thicknesses of the perovskite layers to achieve current matching between both perovskite subcells. Using perovskites with bandgaps optimized for planar surfaces, it would be possible to increase the photocurrent density to 13.3 mA cm−2 and the efficiency to 41.9%. It is shown that by implementing a fully textured structure and using the best available materials, a short‐circuit current of 14.1 mA cm−2 and an open‐circuit voltage of 3.48 V with an efficiency of 44.3% are possible assuming idealized electrical properties. This can be regarded as a practical efficiency potential for this kind of triple‐junction technology. [ABSTRACT FROM AUTHOR]

Recently the development trend in the PV industry is towards much larger wafer formats. With increasing wafer area and the resulting increase in short-circuit current at the cell level, there is also a trend towards sub-cells (solar cell cut into smaller pieces) for module integration. Using sub-cells, the resistance losses through the connection can be reduced. Modules based on sub-cells achieve higher levels of fill factors and thus a higher nominal power. However, the energy yield of such sub-cells is reduced compared to full cells due to the non-passivated laser edge. The laser cut edge causes a high recombination of the charge carriers, which negatively affects the pseudo fill factor as well as open-circuit voltage of the cell. The current work introduces two different approaches for passivating the laser separated PERC solar cells. The experiments were performed on p-type PERC monofacial cells and laser scribe and mechanical cleavage (LSMC) technique was used to obtain sub-cells from the host cells. The method 'laser scribing and simultaneous Al doping' increases the pFF of the cleaved cells by +0.2–0.4%abs in comparison to the reference cleaved cells whereas the method 'laser scribing and subsequent Al doping' shows an improvement in efficiency of the cleaved cells by + 0.2% abs. [ABSTRACT FROM AUTHOR]

Wide‐bandgap metal compound‐based dopant‐free passivating contacts have been explored to fabricate crystalline silicon (Si) solar cells to mitigate the high carrier recombination rate of metal‐Si contact directly. Here, an over 4‐nm‐thick single‐layer strontium fluoride (SrFx) and a double‐layer SrFx/lithium fluoride (LiF) films deposited by a facile vacuum thermal evaporation are developed to act as high‐performance electron‐selective contacts. SrFx with ultra‐low work function (2.8 eV) induces a strong downward band bending at the n‐type Si (n‐Si)/SrFx interface, and a dipole active layer exists at the SrFx/aluminum (Al) interface, enabling a low contact resistivity (ρc) of 34.1 mΩ cm2 and thus yielding an impressive fill factor (FF) of 82.8%. Eventually, a power conversion efficiency (PCE) of 20.1% is achieved in the SrFx‐based solar cell. Moreover, in the n‐Si/SrFx/LiF/Al contact, the diffusion of Li in the SrFx film favors facilitating electron transport as well as relaxing its thickness restriction, inhibiting carrier recombination. And an impressive FF of 83.7% with a low ρc of 25.9 mΩ cm2, an improved open‐circuit voltage of 631 mV, and a short‐circuit current density of 39.9 mA/cm2 are attained, resulting in a champion PCE of 21.1%. Double‐layer SrFx/LiF deposited by a simple process provides a grand opportunity to fabricate low‐cost and high‐PCE photovoltaic devices. [ABSTRACT FROM AUTHOR]

Thin films of transition metal oxides such as molybdenum oxide (MoOx) are attractive for application in silicon heterojunction solar cells for their potential to yield large short‐circuit current density. However, full control of electrical properties of thin MoOx layers must be mastered to obtain an efficient hole collector. Here, we show that the key to control the MoOx layer quality is the interface between the MoOx and the hydrogenated intrinsic amorphous silicon passivation layer underneath. By means of ab initio modelling, we demonstrate a dipole at such interface and study its minimization in terms of work function variation to enable high performance hole transport. We apply this knowledge to experimentally tailor the oxygen content in MoOx by plasma treatments (PTs). PTs act as a barrier to oxygen diffusion/reaction and result in optimal electrical properties of the MoOx hole collector. With this approach, we can thin down the MoOx thickness to 1.7 nm and demonstrate short‐circuit current density well above 40 mA/cm2 and a champion device exhibiting 23.83% conversion efficiency. [ABSTRACT FROM AUTHOR]

Bismuth triiodide is a lead-free direct wide-bandgap solution-processable semiconductor that could be an alternative to lead-based perovskites in tandem or multijunction solar cells. However, the power conversion efficiency of single-junction BiI3 solar cells remains low. Here, we determine the main loss mechanisms of BiI3 solar cells in both n-i-p and p-i-n architectures. Overall, p-i-n devices have higher power conversion efficiency than that of n-i-p. It is found that n-i-p devices have higher (and significant) non-radiative recombination at the interface of the BiI3/transport layer, resulting in a lower open-circuit voltage than p-i-n devices. Moreover, the high series resistance (>70 Ω cm2) and a low average electron–hole diffusion length (∼60 nm) contributes to the low short-circuit current density (<5 mA/cm2) and fill factor (<40%) in all devices. In addition, interface recombination also reduces short-circuit current density. Finally, we demonstrate that lithium doping of BiI3 can increase the diffusion length of BiI3 to improve the performance of BiI3 solar cells. Solar cells with the configuration ITO/NiOx/Li:BiI3/PC61BM/bis-C60/LiF/Ag obtain a power conversion efficiency of 1.3% under AM 1.5 G illumination. The deep understanding of the main loss mechanisms of this work paves the way for future optimization of BiI3 solar cells. [ABSTRACT FROM AUTHOR]

Through the analysis of scales on the drift–diffusion device model of a planar-structured perovskite solar cell, we have obtained accurate-analytical expressions that capture the recombination losses within the cell. The recombination losses are resolved into the radiative and Shockley–Read–Hall mechanisms, as well as interfacial recombination between the perovskite and electron/hole-transporting layers. After parameter calibration with the state of the art planar perovskite solar cell of 23.5% efficiency, the percentage contribution of various recombination loss channels within a planar-structured perovskite solar cell is analytically determined through derived scales and numerically verified at the condition of an open-circuit voltage and a short-circuit current, as well as gives a good prediction of a dominant recombination mechanism within the cell. On this basis, a comparison of loss analysis between the estimated scales and numeric results is carried out at the condition of an open-circuit voltage when a wide range of parameters influencing the recombination current is deviated simultaneously, and a good agreement is obtained. [ABSTRACT FROM AUTHOR]

Barium di-silicide (BaSi2) material has attracted noteworthy interest in photovoltaics, thanks to its stability, abundant nature, and excellent production feasibility. In this current work, a two-terminal (2T) monolithic all-BaSi2 tandem solar cell is proposed and explored through extensive TCAD simulation. A BaSi2 bottom sub-cell with a bandgap of 1.3 eV, and a Ba(CxSi1−x)2 top sub-cell with a tunable bandgap are employed in the design. It was found that a bandgap of 1.8 eV, which corresponds to x = 0.78, is the optimum choice to obtain the maximum initial power conversion efficiency (η) of 30%. Then, the tandem performance is optimized by investigating the impact of doping and the thickness of both absorber layers. Further, the current matching point is monitored whilst altering the thickness of the top cell resulting in η = 32.83%%, and a short-circuit current density (Jsc) of 16.47 mA/cm2. Additionally, we have explored the influence of the defect density in the absorbers, and the work function of contacts on the performance parameters. All TCAD simulations are accomplished using the Silvaco Atlas package under AM1.5G illumination. [ABSTRACT FROM AUTHOR]

In recent years, demand for solar generators for LEO (Low Earth Orbit) applications has been growing, and much research has focused on the use of less expensive and thinner (<90 μm). silicon-based solar cells that can be integrated on flexible Photovoltaic Assemblies (PVAs). These solar cells must be protected from space UV radiations and also withstand more than 50,000 thermal cycles in LEO. The solution advocated here involves the incorporation of UV-absorbing particles into a spatial polymer, combined with lanthanide ions based inorganic phosphors (Y 2 O 3 :Eu3+ and Y 2 O 2 S:Eu3+) to achieve the down-conversion process. Embedded into a silicone-based polymer matrix with a thickness close to 100 μm, these particles are then deposited on 180 μm thick Ga-doped heterojunction silicon cells (30x30 mm2). UV tests are carried out on ONERA's SEMIRAMIS platform at two doses: 425 esh and 1005 esh. A series of 1000 thermal cycles is carried out at the CEA. The first spatial UV analysis revealed a maximum loss of almost 5 % in short-circuit current (Isc) for PV devices after 1005 esh. Comparing results in open circuit voltage (Voc), the bare cell degrades as the dose increases (−2 % at 425 esh and −5 % at 1005 esh). One positive point is that the addition of TiO 2 particles protects the solar cell. These initial results point out that it is possible to produce a protective coating to limit the effects of degradation of Silicon cells under space UV flux, with a focus on producing flexible PVAs. • Space UV resistant frontsheets for photovoltaic arrays based on Silicon solar cells. • Reduced degradation electrical performance after UV exposure with Ti0 2 particles. • Evaluation under space UV radiations of down-converters and absorbing particles. • Behaviors of UV resistant frontsheets with Low Earth Orbit thermal constraints. [ABSTRACT FROM AUTHOR]

This work aims at the full recovery of efficiency losses induced by shingling double-side poly-Si/SiOx passivated contacts crystalline silicon solar cells. It focuses on thermally-activated Aluminium Oxide (AlOx) layers elaborated by thermal Atomic Layer Deposition (ALD) to passivate the edges of shingled cells cut by using the innovative "45° tilt squaring approach". The whole procedure featuring high-temperature AlOx annealing led to very low cut-related performance losses. Indeed, the efficiency and FF of the passivated shingled cells surpassed the values obtained for the as-cut shingles by 0.5%abs and 2.6%abs, respectively. Approaches for further improvements are also discussed, particularly to overcome the short-circuit current density decrease observed for passivated shingles. [ABSTRACT FROM AUTHOR]

Theoretical modeling of the optical and photovoltaic characteristics of highly efficient textured silicon solar cells (SC), including short-circuit current, open-circuit voltage and photoconversion efficiency, has been performed in this work. In the modeling, such recombination mechanisms as non-radiative exciton recombination relative to the Auger mechanism with the participation of a deep recombination level and recombination in the space charge region (SCR) was additionally taken into account. In a simple approximation, the external quantum efficiency of the photocurrent for the indicated SC in the long-wavelength absorption region has been simulated. A theory has been proposed for calculating the thickness dependences of short-circuit current, open-circuit voltage and photoconversion efficiency in them. The calculated dependences are carefully compared with the experimental results obtained for SC with the p + -i-α-Si:H/n-c-Si/i-n + -α-Si:H architecture and the photoconversion efficiency of about 23%. As a result of this comparison, good agreement between the theoretical and calculated dependences has been obtained. It has been ascertained that without taking into account recombination in SCR, a quantitative agreement between the experimental and theoretical light I-V characteristics and the dependence of the output power in the SC load on the voltage on it cannot be obtained. The proposed approach and the obtained results can be used to optimize the characteristics of textured SC based on monocrystalline silicon. [ABSTRACT FROM AUTHOR]

While the first generation of silicon solar cells offers a clean and unlimited energy source, the technology has matured where costs dominate, and the theoretical power conversion efficiency is reaching its limits. The new generation of thin-film solar cells is emerging as an affordable alternative to their bulky counterparts. The technology offers a much cheaper method to quickly fabricate solar cells that use less material with good optical and electronic properties on a wide range of substrates, including flexible materials. In particular, Cu (InxGa1−x) (Se)2 thin-film solar cells are investigated using SCAPS simulation to study the impact of series resistance and doping levels of different layers of the cell structure on the short-circuit current, open-circuit voltage, power conversion efficiency, and fill factor. It was found that an increase in the series resistance of the solar cell layers results in a decrease in the power conversion efficiency with a dependency on light intensities. In addition, the doping level in the absorber and buffer layers plays a significant role in controlling the solar cell's power conversion efficiency and fill factor values with maximum values when acceptor doping levels are approximately equal to donor doping levels. [ABSTRACT FROM AUTHOR]

This study investigates the optimization of printing conditions for n-TOPCon (n-type Tunnel Oxide Passivated Contact) solar cells to enhance their efficiency and performance. Key parameters varied include, dot print type, co-firing belt speed, and paste application method. Experiments conducted on n-type Cz silicon wafers analyzed the impact of high-temperature TOPCon Ag paste and low-temperature HIT (Heterojunction with Intrinsic Thin layer) paste on cell performance. The highest efficiency of 22.57 % was achieved at a belt speed of 100 ipm (inch per minute) with the incorporation of low-temperature HIT paste in a single dot printing configuration. Similarly, at 130 ipm, an efficiency of 22.15 % was obtained under optimized conditions. The fill factor (FF) significantly improved, achieving an FF of 79.66 % at 100 ipm and 78.63 % at 130 ipm. The optimal belt speed of 130 ipm was found to offer the best compromise between enhancing cell efficiency and minimizing potential thermal damage. The best short-circuit current density (J sc) of 41.70 mA/cm2 was achieved at 100 ipm, while the highest open-circuit voltage (Voc) of 0.69007 V was recorded at 130 ipm. Loss analysis indicated that efficiency and FF improvements were primarily driven by superior passivation and reduced contact resistance. This comprehensive study underscores the critical role of optimizing printing conditions to enhance n-TOPCon solar cell efficiency, contributing to more efficient and cost-effective photovoltaic technologies. • At 100 ipm: Dot SP + HIT SP achieved η 22.57 %, V oc 0.68254, FF 79.30 %. • At 130 ipm: Dot SP + HIT DP achieved η 22.15 %, Voc 0.68449 V, FF 78.63 %. • τ dropped from 460 μs to 408 μs after dot printing. • Peak temp and time above 600 °C decreased with higher belt speed. • At 130 ipm: Dot SP + HIT DP: highest FF gain +21.04 %, η gain +5.92 %. [ABSTRACT FROM AUTHOR]

The high-performance silicon solar cells can be manufactured with the unique amorphous/crystalline heterojunction (HJT) structure. In the field applications of the photovoltaics, the durability of HJT modules has become an issue which gets a lot of attention. In this work, it was found that the ultraviolet-induced (UV-induced) degradation is largely caused by the decrease in short-circuit current, and UV cut-off polyolefin elastomers (POE) can effectively suppress the attenuation rate. Additionally, temperature and humidity also affect the module degradation rate, which was revealed through a series of damp-heat (DH) acceleration tests. From the analytical calculations of the data of UV and DH tests, Arrhenius activation energy of 0.43 eV was successfully derived. Accordingly, the Peck model was applied, which indicates that the lifetime of HJT modules can be predicted in the case of the specific climate parameters, such as temperature, humidity and UV irradiation. Based on this model, lifetime of HJT modules is around 22 years due to its stronger annual UV irradiation of over 72 kWh/m2 and over 80 % relative humidity (RH) in Hainan. By contrast, fortunately, lifetime of over 30 years is predicted at the lower UV irradiation of 48 kWh/m2 in Daqing and lower humidity of less than 55%RH in Ningxia, which are the typical photovoltaic climate zones of China. • UV-Cut off encapsulant is imperative in order to obtain the good reliability of HJT module. • Arrhenius activation energy of 0.43 eV was derived through UV and DH tests. • The lifetime of HJT module could be predicted by the improved peck model. [ABSTRACT FROM AUTHOR]

Crystalline Silicon (c-Si) remains a dominant photovoltaic material in solar cell industry. Currently, scientific and technological advances enable producing the c-Si solar cells (SCs) efficiency close to the fundamental limit. Therefore, combining the experimental results and those of modeling becomes crucial to further progress in improving the efficiency and reducing the cost of photovoltaic systems. We carried out the experimental characterization of the highly-efficient c-Si SCs and compared with the results of modeling. For this purpose, we developed and applied to the samples under investigation the improved theoretical model to optimize characteristics of highly efficient textured solar cells. The model accounts for all recombination mechanisms, including nonradiative exciton recombination by the Auger mechanism via a deep recombination centers and recombination in the space-charge region. To compare the theoretical results with those of experiments, we proposed empirical formula for the external quantum efficiency (EQE), which describes its experimental spectral dependence near the long-wave absorption edge. The proposed approach allows modeling of the short-circuit current and photoconversion efficiency in the textured crystalline silicon solar cells. It has been ascertained that the dependences of the short-circuit current on the open-circuit voltage and the dark current on the applied voltage at V < 0.6 V coincide with each other. The theoretical results, as compared to the experimental ones, allowed us to validate the developed formalism, and were used to optimize the key parameters of SCs, such as the base thickness, doping level and others. In this work, we have further generalized and refined the analytical approach proposed and used by us earlier to analyze high-efficiency solar cells and model their characteristics. [ABSTRACT FROM AUTHOR]

Photovoltaic (PV) technology is ready to become one of the main energy sources of, and contributers to, carbon neutrality by the mid‐21st century. In 2020, a total of 135 GW of PV modules were produced. Crystalline silicon solar cells dominate the world's PV market due to high power conversion efficiency, high stability, and low cost. Silicon heterojunction (SHJ) solar cells are one of the promising technologies for next‐generation crystalline silicon solar cells. Compared to the commercialized homojunction silicon solar cells, SHJ solar cells have higher power conversion efficiency, lower temperature coefficient, and lower manufacturing temperatures. Recently, several new record efficiencies have been achieved. To meet the continued demand for high‐efficiency solar cells, expectations for large‐scale mass production of SHJ solar cells are rising. To approach the efficiency limit and industrialization of SHJ solar cells, serious attempts have been made, yielding higher short‐circuit current, open‐circuit voltage, and fill factor. In this article, these recent advancements are reviewed, which reveals the future roadmap for approaching the efficiency limit. [ABSTRACT FROM AUTHOR]

Nonstoichiometric vanadium oxide V2Ox has been demonstrated to serve as a hole‐selective contact in crystalline silicon solar cells. A reaction between V2Ox deposited by thermal evaporation and silicon can, however, result in a decreased work function (WF) and reduce hole selectivity. A straightforward and workable solution is presented in this study, which partially restores the WF of V2Ox as deposited on silicon and improving solar cell efficiency, avoiding the use of amorphous silicon. Incorporating WOx into the Ag/V2Ox1/Si structure, to form Ag/WOx/V2Ox2/Si, x1

In this work, a silicon nanowire solar cell for efficient light harvesting in the visible and near-infrared regions is introduced. In this structure, the silicon nanowires (SiNWs) are coated with a graphene layer and plasmonic nanoparticles are distributed on the top surface of the silicon substrate layer. The proposed structure is simulated using the finite difference time domain (FDTD) method to determine the performance of the solar cell by calculating the open-circuit voltage, fill factor, short-circuit current density, and power conversion efficiency. The absorbed light energy is compared for different nanoparticle materials, namely Au, Ag, Al, and Cu, and Au NPs give the best performance. Different values of the radius of the Au NP are simulated, namely 30, 40, 50, and 60 nm, to determine the optimum radius, and the effect of excess carrier concentration on the solar cell performance is also tested. The obtained open-circuit voltage is 0.63 V, fill factor is 0.73, short-circuit current density is 41.7 mA/cm2, and power conversion efficiency is 19.0%. The proposed SiNW solar cell improves the overall efficiency by almost 60%. Furthermore, the effects of the NW length and distance between NWs are also studied in this work. Finally, the distribution of the optical power in different layers along the solar cell and for different solar cell structures is also illustrated in this paper. [ABSTRACT FROM AUTHOR]

A three-dimensional computer simulation of flexible double-junction solar cells (SC) consisting of Si wires and p-i-n a-Si:H structures was carried out. The performance dependence on geometrical and electrical parameters was calculated. With an increase in the height of the Si wires, the open-circuit voltage ( V OC ) decreases monotonically for both the bottom Si and the top p-i-n a-Si:H junctions. The short-circuit current density ( J SC ) for the top p-i-n a-Si:H junction increases sharply with Si wire height, and then, it goes into saturation at a wire height of more than 10-15 μm. The absolute value of J SC increases (from 10.2 to 12.7 mA/cm2) with a decrease in the wire diameter (from 2 to 0.5 μm). For the bottom junction based on Si wires, the dependence of J SC on the wire height is determined by the charge carrier lifetime, doping level, and diameter, which can be associated with the effect of complete inversion of the Si wire conductivity type. For tandem SCs, the optimal wire height is 10 μm, at which efficiency of 14% can be achieved for structures based on Si wires with a diameter of 0.5 μm and a charge carrier lifetime of 10 μs. The practical implication of the developed design was experimentally demonstrated. [ABSTRACT FROM AUTHOR]

Wafer thinning is a crucial technique for high‐efficiency solar cells. Herein, an inverted pyramid (IP) texture is prepared on a 35 μm‐thick flexible silicon (Si) wafer with a standard area of 156 × 156 mm2. Based on the experimental results, an ultrathin bifacial passivated emitter and rear cell (PERC) with IP textures using PC1D simulation is designed. The influence of wafer thickness, IP texture, bifacial structure, thickness of the antireflection coating, and doping concentration on device performance is investigated. The results show that the ultrathin IP‐based bifacial PERC possesses better output performance than the traditional cell. Finally, a simulated maximum efficiency of 23.44% is obtained using PC1D software, with an open‐circuit voltage of 0.7127 V and a short‐circuit current of 9.272 A. This ultrathin PERC with IP textures provides an effective way to improve the efficiency of ultrathin silicon solar cells. [ABSTRACT FROM AUTHOR]

Herein, it is demonstrated that low temperature current injection and annealing (CIA) treatment can cause evident improvements in open circuit voltage, short‐circuit current, and fill factor of tunnel oxide‐passivated contact (TOPCon) silicon solar cells, leading to a notable conversion efficiency gain (over 0.4% absolute at the best condition). The effects of injected current and annealing temperatures toward the improvement of electrical performance of the TOPCon solar cells are compared. The more evident increase in the electrical performance after the CIA treatment may come from the higher fill factor improvements, which can be induced by the change of contact resistance after the CIA treatment, the potential involvement of hydrogen is discussed. The CIA treatment can be a reliable approach to further enhance the conversion efficiency of TOPCon solar cells, which is of great significance for the global PV industry. [ABSTRACT FROM AUTHOR]

Hydrogenated nanocrystalline silicon (nc‐Si:H) or hydrogenated nanocrystalline silicon oxide (nc‐SiOx:H) as window layers have ample potential to improve the short‐circuit current density (JSC) of silicon heterojunction (SHJ) solar cells due to their wide optical bandgap. However, the growth of their nanocrystals within a 20 nm‐thickness on intrinsic hydrogenated amorphous silicon (i‐a‐Si:H) poses a challenge. Plasma treatment (PT) after i‐a‐Si:H deposition is usually used to improve passivation performance. Herein, the i/p interface is subjected to CO2 PT: a 20 s post CO2 PT is proven to be beneficial in obtaining improved passivation performance. This can be achieved by activated hydrogen which can be diffused to the wafer surface and can saturate the dangling bonds on it. Extending the CO2 PT time from 20 to 40 s, the oxygen (O) insertion into i‐a‐Si:H starts to increase slowly, which leads to marginal change of microstructure in the p layer. Strained SiSi bonds by oxygen incorporation into the a‐Si:H network generate nucleation sites and consequently accelerate the nucleation of p‐nc‐Si:H on i‐a‐Si:H. Finally, it is demonstrated that the power conversion efficiency (PCE) of planar SHJ solar cells is enhanced from 12.65% to 19.06% by a 20 s CO2 PT at the i/p interface. [ABSTRACT FROM AUTHOR]

The emitter is one of the most crucial issues to achieve high-performance silicon heterojunction (SHJ) solar cells. In this work, we study the effects of single-layer and multi-layer p-type emitters, including boron-doped hydrogenated nanocrystalline silicon (nc-Si:H) and/or boron-doped hydrogenated nanocrystalline silicon oxide (nc-SiOX:H) films, on the device performance of SHJ solar cells. The results demonstrate that the sandwich-like p-type emitters of p-nc-Si:H/p-nc-SiOX:H/p+-nc-Si:H have the potential to become an effective and efficient candidate to result in higher efficiency. The lightly boron-doped p-nc-Si:H is used to reduce the incubation layer thickness in the initial stage of growth, while the low parasitic absorption of the p-nc-SiOX:H emitter leads to an increase in short-circuit current. Moreover, a highly boron-doped p+-nc-Si:H layer is implemented on top of the p-nc-SiOX:H to get a lower series resistance (Rs) and higher fill factor. Lastly, we achieve a champion SHJ solar cell on planar wafer with an open-circuit voltage of 678.2 mV, a short-circuit current density of 36.6 mA/cm2, a fill factor of 77% and a conversion efficiency of 19.11%.Kindly check and confirm the ON for the affiliation 1 and 2.We confirm the accuracy of the affiliations. [ABSTRACT FROM AUTHOR]

Optical loss is still a tough problem in photovoltaic; it considerably restrains the conversion efficiency of tunnel oxide passivated contact (TOPCon) solar cells. Black silicon is widely used to enhance light absorption by its light-trapping structure. Paradoxically, the structure simultaneously brings severe carrier recombination and rarely increases efficiency. In our work, we combined the black silicon with TOPCon solar cell and fabricated high-efficiency TOPCon solar cells with nanopore pyramid structure emitter prepared by reactive ion etching. We systematically analyzed the boron doping, emitter passivation, and cell performance. By excellent passivation effect provided by Al2O3/SiNX stacked layers and artificially adjusting boron diffusion process, we successfully fabricated the large-scale (158.75 × 158.75 mm2) bifacial TOPCon solar cells with short-circuit current density of 40.69 mA/cm2 and average conversion efficiency of 23.01% with industrial equipment and processes. [ABSTRACT FROM AUTHOR]

• A novel metallized silver paste with a capillary suspension structure has been developed for use in the front of solar cells. It is suitable for screen printing and laser pattern transfer technology. • In comparison to previous transfer results, it has a larger aspect ratio of 0.63. In contrast to the conventional commercial silver paste, the transfer power is diminished by 80–100 W. • The silver paste in question exhibits higher J sc and lower line resistance in actual production. The results of the simulation demonstrate that the cells exhibit enhanced electrical performance. With the increase in the use of crystalline silicon solar cells, it is necessary for solar cells to achieve finer and higher pre-metallization finger lines. The application of capillary suspension can alter the paste from a weakly elastic state to a highly elastic or even gel-like behavior. The preparation of a frontal silver paste based on a capillary suspension is beneficial in adjusting the rheological properties of the silver paste over a wider range. Two distinct printing methods were employed: screen-printing and laser-pattern transfer printing (PTP). Combined with the results of material, rheology and printing, the optimization of capillary suspended silver paste was explored. This article mainly introduces the elements of silver paste formation in capillary suspension and the effects of PTP technology. The metalized finger line achieved an aspect ratio of 0.63 and a transfer yield of 96 % through PTP. Compared to commercial silver paste for comparison, the transfer power is reduced by 80–100 W while achieving good transfer. It reduces the line resistance of the cell and increases the short-circuit current density (J sc). Following the simulation of the electrical performance of the cells' post-transfer, there was observed to be an improvement in J sc , V oc , and Eta in comparison to the performance of commercial silver paste. [ABSTRACT FROM AUTHOR]

• The surface light management techniques were used on both the solar cell and module to improve light absorption for flexible modules. • The vacuum hot-embossing process is used to prepare anti-reflective units on the front surface of PV module, resulting in a substantial maximum increase of 1.1% in J sc and 1.09% in EQE. • The flexibility of PV module was substantially improved with lower elastic modulus and lower thickness encapsulants. • The electrical properties of the flexible modules were not deteriorated even after 1000 repeated bending tests. Flexible silicon heterojunction (SHJ) solar cells have attracted considerable attention for their suitability in lightweight and flexible module applications owing to their bendable properties. One of the most significant challenges in producing flexible SHJ solar cells and modules is enhancing their light absorption characteristics, particularly when using thinner wafers. In this study, we implemented surface light management techniques at both the solar cell and module levels to improve light absorption. A MgF 2 /TCO antireflection structure was optimized for flexible SHJ solar cells, improving its external quantum efficiency (EQE) and short-circuit current density (J sc) by 2.79% and 1.50%, respectively. Additionally, a vacuum hot-embossing process was incorporated into the front surface of flexible SHJ solar modules, incorporating various sizes of semi-elliptical anti-reflective units. This approach yielded a substantial maximum increase of 1.1% in J sc and 1.09% in EQE for flexible modules. Furthermore, the radiation characteristics of flexible SHJ solar modules placed at different incident light angles and conducted stress analyses under bending conditions were also investigated. The findings revealed that flexibility was substantially improved with lower elastic modulus and lower thickness encapsulants. The electrical properties of the flexible modules were not deteriorated even after 1000 cycles of repeated bending tests. This study successfully addressed the bottlenecks encountered during the development of flexible crystalline silicon (c-Si) photovoltaics (PV) while highlighting the immense potential of these PVs for integrated applications. [ABSTRACT FROM AUTHOR]

• Current density of a HJT solar cell is significantly improved by asymmetrical surface structures. • The basic strategy of changing pyramid bottom angles was proposed. • An innovative stack mask approach was developed to circumvent the interface problems. • Passivation mechanisms of different morphology were discussed in detail. Silicon heterojunction (SHJ) solar cell technology has recently made great progress in mass production. In particular, the average power conversion efficiency (PCE) of mass-produced solar cells has reached nearly 24%. However, the low short-circuit current density (Jsc), a drawback of the SHJ solar cells, has become a bottleneck limiting its further efficiency breakthrough. Therefore, an effective light trapping method is urgently needed for mass-produced SHJ solar cells. In this work, an innovative stacked mask method is developed and combined with a two-step texturing (TST) method to prepare micro-pyramid structures on the front and back side of SHJ solar cells with different pyramid bottom angles, respectively. This asymmetrical structure fabricated through stacked mask method significantly improves the light trapping effect without negative influence on the surface passivation effect. The optical and electrical properties of the SHJ solar cells with this asymmetrical structure under the front side illumination are discussed in detail. It is concluded that the smaller the bottom angle of the backside pyramid, the thinner the amorphous silicon passivation layer is required and the better the surface passivation quality is obtained. The external quantum efficiency (EQE) results demonstrate that the best bottom angle of backside pyramids corresponding to the optimum light trapping effect for the front side illumination is about 16°, which is consistent with the simulation results of the ray tracer. As for the optimal asymmetric structure, the Jsc of the mass-produced SHJ solar cell is improved by 0.36 mA/cm2 and the PCE is increased over 24%. [ABSTRACT FROM AUTHOR]

p‐Type silicon solar cells with a structure of passivated emitter and rear cell (PERC) are a mainstream product of the photovoltaic (PV) industry. Because of its low cost, PERC technology will continue to be dominant for a long time. One of the key features to improve PERC solar cell performance is the use of a selective emitter (SE), which is now mainly realized by laser doping (LD). However, SE by LD still cannot perfectly resolve recombination underneath the front metallized area. The use of a tunnel oxide passivated contact (TOPCon) can dramatically reduce recombination at the metallized area. With the help of an organic mask and etching by texturing solution, the TOPCon SE structure on PERC cells is realized. An average efficiency of 22.65% is reached on 6 in., commercial grade p‐type Czochralski wafers. The average open‐circuit voltage of PERC cells with TOPCon SE is 14.6 mV higher than LD SE. However, the short‐circuit current is lowered by parasitic absorption of polysilicon of alignment margins, which makes cell efficiency of the two SE structures almost the same. With improved alignment precision, TOPCon SE will provide an increase in efficiency. [ABSTRACT FROM AUTHOR]

Various types of potential‐induced degradation (PID) with fundamentally different physical root causes have been observed recently ranging from shunting (PID‐s), corrosion (PID‐c) to degradation of surface passivation (PID‐p). Herein, PID‐p is investigated for the first time at the rear side of bifacial silicon solar cells with enhanced time‐resolution during degradation and recovery under simultaneous illumination. The tests reveal fast transient changes of rear‐side short‐circuit current within minutes and thus allow to understand the degradation process related to PID‐p. The short‐circuit current with rear‐side illumination first decreases significantly by more than 80 % resulting in an intermediate degraded state. Subsequently, it increases to a regenerated state. Under reversed bias, a total recovery of the cell parameters is observed and confirmed by I–V measurements under standard testing conditions (STCs). The underlying transient PID‐p degradation and recovery mechanism is well described by a PC‐1D simulation of the field‐induced band bending at the rear surface. Finally, a qualitative model involving the migration of mobile charged species and their impact on the charge equilibrium in the field effect passivation layer is presented. Thus, time‐resolved analysis of transient PID effects can serve as a clear characteristic for PID of polarization type. [ABSTRACT FROM AUTHOR]

In this article, the synthesis of phase pure iron pyrite nanocubes (FeS2 NCs) and their various effects on the charge carrier dynamics and photovoltaic performances of P3HT:PC71BM based hybrid bulk-heterojunction solar cells have been studied. The optimum doping concentration of FeS2 NCs was found to be 0.3 wt%. For the optimally doped devices, the short-circuit current density was found to have improved from 5.47 to 7.99 mA cm−2 leading to an overall cell efficiency improvement from 2.10% to 3.22% as compared to the undoped reference devices. The enhancement in photovoltaic performance is mainly attributed to the formation of localized energy states near the band edges leading to higher carrier generation rate by 72% whereas carrier dissociation probability is also increased by 13%. Urbach energy estimation reveals that the optimally doped devices have achieved a relatively balanced amount of localized states resulting in reduced non-radiative recombination. Such localized defect states formation with FeS2 NCs doping was also found to have significant influence over the charge carrier dynamics of the active layer. Transient photocurrent and photovoltage studies revealed that FeS2 NCs assist in faster carrier extraction by reducing the transport time from 1.4 to 0.6 μs and by enhancing carrier recombination time from 51.7 to 78.9 μs for the reference and optimum devices respectively. Such an unorthodox approach of defect state assisted efficiency improvement demonstrates the importance of simultaneously understanding the charge carrier dynamics and photovoltaic performance for rational device optimization, and opens new prospects for developing high-efficiency solution processable hybrid devices. [ABSTRACT FROM AUTHOR]

As a variety of non‐fullerene small molecule acceptors (SMAs) have been developed to improve power conversion efficiency (PCE) of organic solar cells (OSCs), the pairing of the SMAs with optimal polymer donors (PDs) is an important issue. Herein, a systematic investigation is conducted with the development of the SMA series, named C6OB‐H, C6OB‐Me, and C6OB‐F, which contain distinctive terminal substituents –H, –CH3, and –F, respectively. These SMAs are paired with two PDs, PBDT‐H and PBDT‐F. Interestingly, the PD/SMA pairs with similar terminal groups yield enhanced molecular compatibility and energetic interactions, which suppress voltage loss while improving blend morphology to enhance simultaneously the open–circuit voltage, short–circuit current, and fill factor of the OSCs. In particular, the OSC based on the PBDT‐F:C6OB‐F blend sharing fluorine terminal groups achieves the highest PCE of 15.2%, which outperforms those of PBDT‐H:C6OB‐F (10.1%) and PBDB‐F:C6OB‐H OSCs (11.2%). Furthermore, the PBDT‐F:C6OB‐F OSC maintains high PCEs with active layer thicknesses between 85 and 310 nm. In contrast, the PCE of PBDT‐H:C6OB‐F‐based OSC already drops by 80% from 10.1% to 2.1% when the active layer thickness increases from 100 to 200 nm. This study establishes an important PD/SMA pairing rule in terms of terminal functional groups for achieving high‐performance OSC. [ABSTRACT FROM AUTHOR]

As the performance of organic–inorganic halide perovskite solar cells approaches their practical limits, the use of back‐contact architectures, which eliminate parasitic light absorption, provides an effective route toward higher device efficiencies. However, a poor understanding of the underlying device physics has limited further performance improvements. Here a mesoporous charge‐transporting layer is introduced into quasi‐interdigitated back‐contact perovskite devices and the charge extraction behavior with an increased interfacial contact area is studied. The results show that the incorporation of a thin mesoporous titanium dioxide layer significantly shortens the charge‐transfer lifetime and results in more efficient and balanced charge extraction dynamics. A high short‐circuit current density of 21.3 mA cm–2 is achieved using a polycrystalline perovskite layer on a mesoscopic quasi‐interdigitated back‐contact electrode, a record for this type of device architecture. [ABSTRACT FROM AUTHOR]

[Display omitted] • Texture morphology has impacts on the silicon heterojunction solar cell performance. • Small pyramidal texture has good uniformity of the pyramid size distribution. • Uniform pyramidal texture is highly anti-reflective and can be passivated well. • Uniform small pyramidal texture brings the solar cell high J SC and V OC , but low FF. • Low FF is due to the increased contact resistance of the TCO/Ag interface with voids. By adjusting the KOH/H 2 O texturing condition intendedly, different random pyramidal textures with the average pyramid size of 8 μm (large), 4 μm (medium) and 1.5 μm (small) were prepared on N type M2 monocrystalline silicon substrates for the fabrication of silicon heterojunction (SHJ) solar cell. It was evidenced that the pyramid morphology not only impacted the reflection of incident light and the heterojunction interface passivation quality but also affected the interface contact property between transparent conductive oxide (TCO) layer and Ag electrode. The texture with small pyramids presented the best anti-reflective and passivation performance due to the pyramidal size distribution uniformity, which brought the SHJ solar cell the highest short-circuit current density (J SC) and open-circuit voltage (V OC). However, the texture with small pyramids also led to the worst fill factor (FF). As a result, there was no obvious difference on the conversion efficiency for the textures with different pyramidal size. By characterizing the TCO/Ag contact, the FF reduction induced by the small pyramid texture could be attributed to the increased specific contact resistance of the TCO/Ag contact, which resulted from the fact that there were lots of voids between the TCO layer and Ag electrode, since Ag particles with a larger size than the small pyramids could not fill into the limited space between the adjacent pyramids. As a result, in order to realize the potential to enhance the SHJ solar cell conversion efficiency by adopting the texture with small pyramids, new Ag paste with smaller Ag particles should be adopted. [ABSTRACT FROM AUTHOR]

The tandem structure is promising to break the Shockley–Queisser limit of single-junction solar cells. Optical management is essential in two-terminal (2T) tandem devices to equalize the current of each sub-cell and enhance the performance. In this work, the photon redistribution effect caused by the optical coupling layer (OCL) and its impact on 2T perovskite/Si tandem solar cells are systematically investigated. We modulate the overall optical field distribution to balance the current of the two sub-cells by structural modulation. The introduction of an OCL affects the photon distribution in the 2T tandem device, which disturbs the original current match and complicates the optical management. In addition to the antireflection function, the photon redistribution effect due to the coupling effects exists for each type of OCL. Various materials (LiF, MgF2, Al2O3 and ZnO) are employed as OCLs and compared. It is shown that they influence the device performance to different degrees. Compared to LiF and MgF2, the influence of the 2T tandem device on short-circuit current density is more significant when Al2O3 and ZnO act as OCLs. By investigating the optical mechanism and then improving the optical management, an optimized device performance can be achieved. We believe that it is necessary to consider the coupling effect in the structural design of 2T tandem solar cells. [ABSTRACT FROM AUTHOR]

Chemical modifications of non‐fullerene acceptors (NFAs) play vital roles in the development of high efficiency organic solar cells (OSCs). In this work, on the basis of the previously reported molecule named Y6‐1O, chlorination and inner side‐chain engineering are adopted to endow the corresponding devices with higher open‐circuit voltage (VOC) and short‐circuit current density (JSC) as well as good morphology for high fill factor (FF). As a result, the molecule named BTP1O‐4Cl‐C12 can help achieve a higher power conversion efficiency (PCE) of 17.1% than that of Y6‐1O (16.1%). Furthermore, the following comparisons between BTP1O‐4Cl‐C12 and the two symmetric acceptors named BTP2O‐4Cl‐C12 and BTP‐4Cl‐C12 demonstrate the effect of asymmetric alkoxy substitution on the outer side chains, which not only achieves a balance between VOC and JSC, but also help obtain appropriate morphology for efficient charge dissociation and suppressed charge recombination. Therefore, the asymmetric BTP1O‐4Cl‐C12 can achieve a higher PCE compared to the symmetric BTP2O‐4Cl‐C12 and BTP‐4Cl‐C12. The work not only reports an excellent NFA for high‐performance OSCs, but also puts forward a series of methods for consecutive chemical modifications on Y‐series acceptors, which can be further applied to boost the PCE of OSCs to a higher level. [ABSTRACT FROM AUTHOR]

[Display omitted] • Efficiency of Sb 2 S 3 solar cell is improved by optimizing VTD source-substrate proximity. • Non-ohmic shunt current might affect the performance of Sb 2 S 3 solar cells significantly. • The carrier recombination rates are lowest for the optimal source-substrate proximity cell. In this paper, Sb 2 S 3 thin-film solar cells are fabricated by the vapor transport deposition (VTD) method. The effect of the source-substrate proximity on the performance of Sb 2 S 3 thin-film solar cells has been investigated and comparative studies of different source-substrate proximity are carried out. The device efficiency is improved from 0.83 to 3.02% by optimizing the source-substrate proximity with the augment of open-circuit voltage, short-circuit current density and fill factor. X-ray diffraction and scanning electron microscopy studies indicate that the deposited Sb 2 S 3 films can achieve optimal grain orientation, high crystallinity, and compact morphology. Moreover, the current transport mechanism is analyzed in detail from dark current density–voltage (J-V) measurements and shows the optimal sample to be least affected by Shockley-Read-Hall recombination and space-charge-limited current (SCLC). Meanwhile, temperature and light intensity-dependent open-circuit voltage measurements reveal the carrier recombination rates are lowest for the optimal cell in all regions, including the CdS/Sb 2 S 3 interface, the space-charge region (SCR), and the quasi-neutral region (QNR). These can account for the efficiency enhancement of the optimal cell and can be used to facilitate the further development of Sb 2 S 3 thin-film solar cells. [ABSTRACT FROM AUTHOR]

CdTe is the leading commercial thin film photovoltaic technology with current record laboratory efficiency (22.1%). However, there is much potential for progress toward the Shockley‐Queisser limit (32%). The best CdTe devices have short‐circuit current close to the limit but open‐circuit voltage has much room for improvement. Back contact optimization is likely to play a key role in any improvement. Back contact material choice is also influenced by their applicability in more complex architectures such as bifacial and tandem solar cells, where high visible and/or near‐infrared transparency is required in conjunction with their electrical properties. The CdTe research community has employed many back contact materials and processes to realize them. Excellent reviews of back contacts were published by McCandless and Sites (2011) and Kumar and Rao (2014). There have been numerous publications on CdTe back contacts since 2014. This review includes both recent and older literature to give a comprehensive picture. It includes a categorization of back contact interface materials into groups such as oxides, chalcogenides, pnictides, halides, and organics. The authors attempt to identify the more promising material groups. Attention is drawn to parallels with back contact materials used on other thin film photovoltaics such as perovskites and kesterites. [ABSTRACT FROM AUTHOR]

A passivation strategy for the perovskite/HTL interface is presented based on potassium acetate (K‐Ac). Since K‐Ac is soluble in both polar and nonpolar solvent, deposition of K‐Ac on top and bottom of perovskite is possible. With this advantage, the universality of potassium interfacial passivation at the HTL/perovskite interface applied to various configurations with various ranges of perovskite bandgap is reported. Regarding the p–i–n configuration, various materials characterizations reveal that a potassium passivation layer underneath perovskite modifies perovskite orientations, resulting in better charge transport and film properties. Furthermore, the potassium passivation layer shifts the valence band position of the HTL upward, which results in a better extraction of charges (holes) across the HTL/perovskite interface, thus improving the short‐circuit current density (Jsc). The modification of the band alignment at the HTL/perovskite by the potassium interfacial passivation layer is confirmed in n–i–p devices with both WBG and CBG perovskites. Compared to reference solar cells without a passivation layer, an increase in Jsc of approximately 1 mA cm−2 is observed in all cases, resulting in power conversion efficiencies of 19.42%, 20.06%, and 21.57% for WBG p–i–n, CBG p–i–n and n–i–p solar cells, respectively, demonstrating the wide applicability of the passivation strategy. [ABSTRACT FROM AUTHOR]

Herein, challenges in the fabrication of full dopant‐free bifacial silicon solar cells are discussed and efficient devices utilizing a MoO3/ indium tin oxide (ITO)/Ag hole‐selective contact and ZnO/LiFx/Al electron‐selective contacts with up to 79% short‐circuit current bifaciality are demonstrated. The ZnO/LiFx/Al rear electron contact features a full‐area ZnO antireflective coating and a LiFx/Al finger contact, allowing sunlight absorption from the back side, thus producing more overall power. The ZnO/LiFx/Al electron contacts with a thinner ZnO layer and a larger contact fraction display a better selectivity and a lower resistance loss. When considering rear‐side irradiance of 0.15 sun, the dopant‐free bifacial solar cell with 60 nm ZnO and 50% LiFx/Al metal contact fraction achieves a 3% estimated output power density improvement compared with its monofacial counterpart (21.0 mW cm−2 compared to 20.3 mW cm−2) using the full‐area back contact. Both the efficiency and bifaciality factor of this dopant‐free device are still significantly lower than those of state‐of‐the‐art devices relying on doped‐silicon‐based layers. The required improvement for this technology to become industry‐relevant is discussed. [ABSTRACT FROM AUTHOR]

III–V/Si multi‐junction solar cells are potential successors to the silicon single‐junction cell due to their efficiency potential of up to 40% in the radiative limit.[1] Herein, latest results of epitaxially integrated GaInP/GaAs/Si triple‐junction cells are presented. To reduce parasitic absorption losses, which have limited the current density in the Si bottom cell in the previous devices, transparent AlxGa1–xAsyP1–y step‐graded metamorphic buffers are investigated. Compared with previous GaAsyP1–y step‐graded buffers, the transmittance is enhanced significantly, while no significant impact on the threading dislocation density is observed. Implemented into a new triple‐junction solar cell, an increase in short‐circuit current density from 10.0 to 12.2 mA cm−2 is achieved, leading to a new record conversion efficiency of 25.9% under AM1.5g conditions. [ABSTRACT FROM AUTHOR]

Herein, the synthesis of a new medium bandgap nonfullerene acceptor DBTBT‐IC consisting of di‐benzothieno [3,2‐b][1]‐benzothiophene DBTBT as the central donor unit and IC as terminal acceptor units and its use as the acceptor for the fabrication of single binary and ternary polymer solar cells is reported. DBTBT‐IC exhibits a medium optical bandgap of about 1.65 eV. When paired with the wide bandgap‐conjugated polymer PDTNIT as donor, the polymer solar cells based on the optimized PDTNIT:DBTBT‐IC active layer realized a power conversion efficiency of 12.34% (short‐circuit current = 8.06 mA cm−2, open‐circuit voltage = 1.12 V, and fill factor (FF) = 0.62) which is higher than that for the PDTNIT:PC71BM counterpart, i.e., 9.08 % (short‐circuit current=14.58 mA cm−2, open‐circuit voltage = 0.93 V, and FF = 0.67). When a small amount of PC71BM was introduced into the host PDTNIT:DBTBT‐IC binary layer, the polymer solar cell based on the optimized PDTNIT:PC71BM:DBTBT‐IC (1:0.3:0.9) ternary active layer attained an excellent power conversion efficiency of about 15.92 %, mainly due to the increase in short‐circuit current and FF. The increase in the short‐circuit current may be associated with the broader absorption profile of the ternary active layer as compared with the binary counterparts and more efficient exciton utilization, due the partial energy transfer from PC71BM to DBTBT‐IC. [ABSTRACT FROM AUTHOR]