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The efficiency of antimony selenide (Sb2Se3) solar cells is still limited by significant interface and deep‐level defects, in addition to carrier recombination at the back contact surface. This paper investigates the use of lithium (Li) ions as dopant for Sb2Se3 films, using lithium hydroxide (LiOH) as a dopant medium. Surprisingly, the LiOH solution not only reacts at the back surface of the Sb2Se3 film but also penetrate inside the film along the (Sb4Se6)n molecular chain. First, the Li ions modify the grain boundary's carrier type and create an electric field between p‐type grain interiors and n‐type grain boundary. Second, a gradient band structure is formed along the vertical direction with the diffusion of Li ions. Third, carrier collection and transport are improved at the surface between Sb2Se3 and the Au layer due to the reaction between the film and alkaline solution. Additionally, the diffusion of Li ions increases the crystallinity, orientation, surface evenness, and optical electricity. Ultimately, the efficiency of Sb2Se3 solar cells is improved to 7.57% due to the enhanced carrier extraction, transport, and collection, as well as the reduction of carrier recombination and deep defect density. This efficiency is also a record for CdS/Sb2Se3 solar cells fabricated by rapid thermal evaporation. [ABSTRACT FROM AUTHOR]

Antimony selenide (Sb2Se3) thin film solar cells were prepared by vapor transport deposition, and cesium chloride (CsCl2) solution was used to treat the upper interface of the device. Meanwhile, a series of characterizations of the thin film and the device were also performed. The study shows that the back contact treatment of CsCl2 solution can not only improve the carrier collection and reduce upper interface recombination of the device, but also optimize the crystallinity, surface roughness and optoelectronic performance of thin film. Based on the device structure of FTO/CdS/Sb2Se3/CsCl2/Au, a high-efficiency Sb2Se3 thin film solar cell with efficiency of 6.32% are obtained, which is 12% higher than that of the basic device. The research may provide some guidance to further development of Sb2 Se3 thin film solar cells and other similar types of semiconductor photovoltaic devices. [ABSTRACT FROM AUTHOR]

As the efficiency of perovskite solar cell has skyrocketed to as high as 25.7%, their stability has become the biggest obstacle to commercialization. Preliminary analyses suggest that additive engineering may be effective in improving both solar cell efficiency and its stability. Herein, the plant‐derived natural green additive of l‐Theanine (Thea) is selected to improve the crystal quality of the perovskite absorber and obtain high‐performance perovskite solar cells (PSCs) with ultraviolet/ozone (UV/O3) resistance. The characterization results reveal that the CO group in Thea can effectively inhibit the precipitation of metal Pb0, passivate undercoordinated Pb2+ ions, and promote the nucleation and crystallization of perovskite. In addition, the combination of the NH group and I− in the form of a hydrogen bond cooperatively reduce the probability of nonradiative recombination of photogenerated carriers and effectively improves the extraction ability of carriers from perovskite absorber. With the cooperation of CO and NH2 groups in Thea, the champion efficiency is improved from 22.29% in the control device to 24.58%. More importantly, Thea significantly alleviates the perovskite phase transition and film decomposition induced by UV/O3 treatment. The study provides exploratory research for the application of plant‐derived green additives in the UV/O3 resistance field of perovskite photovoltaics. [ABSTRACT FROM AUTHOR]

Solar cell efficiency and stability are two key metrics to determine whether a photovoltaic device is viable for commercial applications. The surface termination of the perovskite layer plays a pivotal role in not only the photoelectric conversion efficiency (PCE) but also the stability of assembled perovskite solar cells (PSCs). Herein, a strong chelate coordination bond is designed to terminate the surface of the perovskite absorber layer. On the one hand, the ligand anions bind with Pb cations via a bidentate chelating bond to restrict the ion migration, and the chelate surface termination changes the surface from hydrophilic to hydrophobic. Both are beneficial to improving the long‐term stability. On the other hand, the formation of the chelating bonding effectively eliminates the deep‐level defects including PbI and Pb clusters on the Pb‐I and FA‐I terminations, respectively, as confirmed by theoretical simulation and experimental results. Consequently, the PCE is increased to 24.52%, open circuit voltage to 1.19 V, and fill factor to 81.53%; all three are among the highest for hybrid perovskite cells. The present strategy provides a straightforward means to enhance both the PCE and long‐term stability of PSCs. [ABSTRACT FROM AUTHOR]

It has been reported that an overlayer of lower dimensional perovskite can effectively improve the properties of 3D perovskite solar cells. Here, 4‐aminobutyric acid (C4I) and 6‐aminocaproic acid iodides (C6I) are introduced onto the surface of the perovskite layer, forming a low‐dimensional (LD) capping layer on the 3D perovskite films for high‐performance devices. It is found that C4I forms a 2D perovskite layer, while C6I forms a 1D perovskite layer on the 3D perovskite surface. By using the LD capping layers, the integrated perovskite films show passivated surface traps, reduced defect density, improved carrier lifetimes, and altered band alignment, leading to improved fill factor and open‐circuit voltage and, hence, significantly higher device efficiency. The devices with the C4I and C6I capping layers achieve solar cell efficiencies as high as 23.48% and 23.11%, respectively. In addition, bare devices with the C4I and C6I integration maintain 93.73% and 91.58%, respectively, of their initial efficiencies after exposure to the ambient atmosphere for 2000 h, demonstrating much better stability than the pristine 3D holding only 83.30% of its initial efficiency. It appears that this 2D capping is more suitable for enhancing 3D perovskite performance for general photoelectronic applications than the 1D capping. [ABSTRACT FROM AUTHOR]

Inorganic CsPbI2Br perovskite is promising for solar cell applications due to its excellent thermal stability and optoelectronic characteristics. Unfortunately, the current high‐efficiency CsPbI2Br perovskite solar cells (PSCs) are mostly fabricated in an inert atmosphere due to their instability to moisture. Herein, a low‐dimensional intermediate‐assisted growth (LDIAG) method is reported for the deposition of CsPbI2Br film in ambient atmosphere by introducing imidazole halide (IMX: IMI and IMBr) into the precursor solution to control both nucleation and growth kinetics. The IMX first combines with PbI2 in the precursor film to form a 2D intermediate which then gradually releases PbI2 to slowly form high‐quality CsPbI2Br film during annealing. It is found that the LDIAG method produces a uniform, highly crystalline, pinhole‐free, and stable CsPbI2Br film with low defect density. Consequently, the solar cell efficiency is increased to as high as 17.26%, one of the highest for this type of device. Furthermore, the bare device without any encapsulation shows excellent long‐term stability with ≈86% of its initial efficiency retained after being exposed to the ambient environment for 1000 h. This work provides a perspective to tune the intermediate phases and crystallization pathway for high‐performance inorganic PSCs formed under ambient conditions. [ABSTRACT FROM AUTHOR]

Laser-enhanced contact optimisation (LECO) technology can effectively improve the efficiency of tunnel oxide passivated contact (n-TOPCon) solar cells. Generally, the preparation of an emitter in TOPCon cells requires post-oxidation treatment at temperatures exceeding 1030 °C for over 3000 s. This high-temperature post-oxidation process results in reduced surface doping concentration, increased reflectivity of the front of the cell and elevated manufacturing costs of the junction. In this study, through process research, we reveal that the optimal profile depth of emitter (the boron doping concentration at 1 × 1018 atoms/cm3) for mass-produced LECO pastes ranges from 0.44 to 0.52 μm. Additionally, it was discovered that a boron-rich layer (BRL) thinner than 10 nm does not reduce bulk lifetime and increase contact resistivity. Based on these findings, we developed a boron-diffusion method without post-oxidation, which involves controlling the BRL thickness by adjusting the pre-oxidation layer thickness and cycle deposition. When applied to the mass production of n-TOPCon solar cells, this approach resulted in a solar cell conversion efficiency of 26.28 %. This represents an improvement of 0.03 %–0.05 % over traditional boron-diffusion processes. Furthermore, eliminating post-oxidation significantly improved the production capacity and lifespan of the boron-diffusion furnace, thereby reducing the manufacturing costs associated with the solar cells. Furthermore, eliminating post-oxidation significantly improved the production capacity and lifespan of the boron-diffusion furnace, thereby reducing the manufacturing costs associated with the solar cells. • The boron-diffusion method without post-oxidation is proposed. • Mass production of n-TOPCon solar cells with efficiency (26.28 %) is obtained. • The production capacity and lifespan of the boron-diffusion furnace is improved. [ABSTRACT FROM AUTHOR]

• Screen-printing Ag paste technology plays an important role in n-TOPCon solar cell. • The energy density threshold of UV pulse laser ablate SiN x were investigated. • The mechanism of Al paste and n+-poly-Si contacts was revealed. • The best efficiency was 22.56% with Al paste (25 wt%-29 wt% silicon). Screen-printing Ag paste on the rear side of the Tunnel Oxide Passivated Contact solar cells (TOPCon) is still the mainstream method to form electrodes. However, the high price of precious metals increases the cost of TOPCon cells. Al is a cheap and high-performance conductor, and its work function is compatible with the rear side of TOPCon cells. In this study, we used a UV pulse laser (355 nm, 10 ps) to ablate the rear side SiN x passivation layer of TOPCon cells and then printed Al paste with different weight percentages of silicon (Si-wt.%) on the phosphorus-doped polycrystalline silicon (n+-poly-Si) layer to reduce the cost. We investigated the damage mechanism of laser on SiO x /n+-poly-Si/SiN x passivation structure and the contact mechanism between Al paste and n+-poly-Si layer. The results show that the V oc of SiO x /n+-poly-Si/SiN x passivation structure reduced about 6–7 mV when the laser energy density was 0.431 J/cm2. We got the best electrical performance of TOPCon cells printed with Al paste (25 wt%-29 wt% silicon). The open-circuit voltage (V oc) and the conversion efficiency (E ff), have reached 663.60 mV and 22.56 % respectively. Although the efficiency was 9.40 % relative lower than that of TOPCon cells printed with Ag paste, but the cost of Al paste only accounted for 10 % of Ag paste. In the future, the highest E ff of TOPCon solar cells printed with Al paste on the rear side are expected to reach the commercial TOPCon based on Ag paste, which applies laser doping selective emitter technology (SE) and bifacial poly-Si passivation structure. [ABSTRACT FROM AUTHOR]

• The B-doped induced recombination encountered in n-TOPCon solar cells. • B-doped profile divided into two characteristics: peak concentration and junction depth. • Cells with junction depth 0.75–1.0 μm and N max 1–1.5 × 1019 atoms/cm3 exhibited the best I-V. • After the optimization of B emitter, the solar cells reached a pilot efficiency greater than 23.4% A big challenge to improve the conversion efficiency of n-type solar cell is the recombination and electrical contacting of boron (B)-doped emitters in n-TOPCon solar cells. This work investigates the emitter dark saturation current density under the passivation layer (J 0e, passivated), the metallization-induced recombination current density under the metal contact (J 0e, metal), and the I – V parameters, including short-circuit current density (J sc), open circuit voltage (V oc), fill factor (FF) and efficiency (E ff) as functions of the peak concentration (N max) and junction depth of B-doped profile. We introduced the profile with the peak concentration of 1–1.5 × 1019 atoms/cm3 and a junction depth of 0.75–1.0 μm to improve the conversion efficiency of 23.4%. The results revealed that J sc, implied V oc (i V oc) and the contact resistance (ρ c) were negative correlated with the N max and junction depth. However, J 0e, passivated had a positive correlation with the same. The results from ρ c , J 0e along with the I – V showed the junction depth of emitter doping profiles need to exceed the corroded depth of Ag/Al paste to get a low ρ c , meanwhile, a low J 0e should be ensured. The results suggested theB-selective emitters were developed with a low ρ c and a low J 0e. After optimizing B-selective emitters and passivation processes, we obtained industry-grade TOPCon cells with E ff , V oc , J sc , and FF as high as 23.7%, 709 mV, 40.8 mA/cm2, and 82%, respectively. This optimized B-doped and simplified B-selective emitters processes can be commercially applied in photovoltaics. [ABSTRACT FROM AUTHOR]

The tunnel oxide passivated contact solar cells (TOPCon) on n-type Cz Si wafers instead of passivated emitter and rear solar cells are currently migrated to mainstream production, with ongoing improvements in recent years. In this study, we investigated and characterized one recent batch of TOPCon cells fabricated on 156.75 × 156.75 × 0.18mm3 wafers with fully screen-printed technology by an industrial-type process. TOPCon cells with an efficiency as high as 22.43%, a Voc value as high as 689.4 mV, and a fill factor as high as 81.35% were obtained. The P dopant diffusion in the poly Si layer as well as the thickness of the SiO x layer were optimized in order to obtain good electrical contact between screen-printed Ag and Si. The thickness of the SiO x layer should be over 1.5 nm, which is beneficial for obtaining a good passivation for the cells. The surface P dopant concentration in the polycrystalline Si was higher than 1 × 1020 atom/cm3, resulted in a low series resistance and a high fill factor. The characterization and simulation results show that both metal shading loss and rear surface recombination were dominant among all of the losses. Application to solar cells with a Voc of 697 mV and a fill factor of 82.45% could lead to an independently confirmed cell efficiency of over 23% for n-type cells with poly Si the herein developed passivated rear contacts, and the front metal contacts by addressing the issue of reducing metal recombination and implementing a selective emitter. • One batch of TOPCon solar cells fabricated by the industrial type process. • Comparison of different SiO x layer thickness for TOPCon solar cells. • Cells with SiO x layer thickness of 1.55nm exhibited the best passivation effect. • Eff, Voc and FF as high as 22.43%, 689.4mV, and 81.35% were obtained, respectively. • Metal shading loss and rear surface recombination were dominant. [ABSTRACT FROM AUTHOR]

• As a hole transporting layer, CuSbSe 2 film has a lower lattice mismatch with Sb 2 Se 3. • CuSbSe 2 film reduces the interface defect concentration and carrier recombination. • A PIN-structured solar cell with an efficiency of 5.87% was obtained. As an excellent light absorbing material, antimony selenide (Sb 2 Se 3) has attracted researchers to explore its application in solar cells. At present, the efficiency of Sb 2 Se 3 solar cells is still too low because of the low carrier concentration and high back surface recombination. In this study, we prepared an additional CuSbSe 2 film as hole transport layer by co-sputtering Sb 2 Se 3 and Cu targets. It reduced the surface roughness of the absorption layer and the back surface recombination, which was beneficial to the collection of carriers. Due to the higher carrier concentration of CuSbSe 2 film and proper diffusion of Cu, the carrier concentration of the absorption layer is greatly improved, thereby effectively increasing the V oc of the Sb 2 Se 3 thin film solar cells. Finally, we obtained a 5.87% efficiency for the FTO/CdS/Sb 2 Se 3 /CuSbSe 2 /Au solar cell, which is more than 25% higher than the basic efficiency. [ABSTRACT FROM AUTHOR]

• Good crystallinity Sb 2 Se 3 films were fabricated by co-sputtering at substrate temperature 350 °C without subsequent annealing. • Vacancies caused by Se loss was decreased by co-sputtering. • Performance of the films improved and achieved an efficiency of 3.47% in solar cell. Antimony selenide (Sb 2 Se 3) has attracted scientific interest due to its many advantages such as its appropriate band gap, non-toxicity, element abundance, and high absorption coefficient (>105 cm−1). However, selenium (Se) is easily lost at high vapor pressures, thus leading to Se vacancies and increased recombination centers in films. In this work, Sb 2 Se 3 films with good crystallinity were fabricated by co-sputtering of Sb 2 Se 3 and Se targets with a substrate temperature of 350 °C and without a subsequent annealing process. The crystal structural properties, surface morphology, and optical and electrical properties of films with different Se contents were explored. Finally, we fabricated solar cells with a structure of FTO/CdS/Sb 2 Se 3 /Au and achieved an efficiency up to 3.47%. [ABSTRACT FROM AUTHOR]

In recent years, Sb 2 Se 3 has gained attention for use in solar cells owing to its excellent optoelectronic properties. However, its development is limited by the toxicity of CdS, which is a traditional buffer layer; hence, non-toxic SnO 2 is adopted. Even so, the low crystallinity and rough surface of SnO 2 films have restricted development. Therefore, we use TiO 2 to improve the crystallinity and reduce the roughness of SnO 2 films. We fabricate a mixed buffer layer comprising SnCl 4 and TiCl 4 in different ratios to replace the pure SnO 2 layer. The best ratio is 1:0.2, for which the power conversion efficiency reaches 4.0%. This laid the foundation for industrial production of the non-toxic Sb 2 Se 3 solar cells. • Both SnO 2 and TiO 2 are non-toxic earth-abundant materials. • We demonstrated a SnO 2 –TiO 2 mixed buffer layer as the buffer layer of Sb 2 Se 3 thin film solar cells. • By adding TiO 2 , the surface roughness of SnO 2 reduced and the crystallinity of SnO 2 grains increased. • By adding TiO 2 , the efficiency of the SnO 2 –TiO 2 /Sb 2 Se 3 solar cell reached 4.0%. [ABSTRACT FROM AUTHOR]

• La doping increased electrical conductivity and crystallinity of SnO 2 film. • PCE of SnO 2 /Sb 2 Se 3 solar cell increased by 31% using La doping. • Increased efficiency is attributed to improved crystallinity and conductivity of SnO 2. Sb 2 Se 3 is a promising photovoltaic material having advantages of suitable bandgap, strong light absorption, simple phase, nontoxicity, and earth-abundant constituents. Different buffer layers were used to fabricate Sb 2 Se 3 solar cells. However, the efficiency of SnO 2 /Sb 2 Se 3 solar cells was limited by the crystallinity and surface roughness of the SnO 2 film. In this study, lanthanum was doped on the SnO 2 film to increase crystallinity and impart surface uniformity. Moreover, the influence of La doping on the solar cell performance was investigated in detail. An average efficiency of 3.25% for the La-doped SnO 2 /Sb 2 Se 3 solar cells was obtained. [ABSTRACT FROM AUTHOR]

An ultrathin Ti film acting as both an intermediate layer and a dopant was inserted at the interface between Mo and Cu 2 ZnSnS 4 (CZTS) to improve the performance of CZTS solar cells. Different from previously reported blocking layers, the Ti intermediate layer inhibited the formation of a MoS 2 layer and voids at the interface between the Mo and CZTS absorber and also influenced the crystallinity, surface evenness, Hall mobility, and absorptivity of the CZTS absorber. When the thickness of the Ti blocking layer increased to 20 nm, the conversion efficiency of the solar cell increased by 57%, along with an increase in the open-circuit voltage of 32%. The effect of the Ti layer on the microstructure and performance of the CZTS film is discussed here in detail. These results serve as guiding principles for preparing high-quality CZTS thin films for potential applications in low-cost solar cells. [ABSTRACT FROM AUTHOR]

Improving the conversion efficiency of n-TOPCon solar cell is still a hot topic. The selective poly-Si based passivating contacts (Poly-SEs) are ideal candidates for reducing the parasitic absorption and contact resistivity of n-type silicon solar cells and for providing better current collection. In this work, we used LPCVD and the POCl 3 tube furnace diffusion methods to fabricate the selective poly-Si based passivating contacts, and studied the influences of key process parameters of the SiO x layer formation process (the oxidation duration (t oxidation) and the constant pressure duration (t pressure)), and POCl 3 tube diffusion process parameters (the POCl 3 -N 2 carrier gas flow rate at the deposition, deposition temperature, drive-in temperature) on the n+-poly-Si profiles, recombination current density (J 0), contact resistivity (ρ c) of n-TOPCon solar cells. The results showed that the t oxidation and t pressure had a significant impact on J 0 and ρ c which were mainly related to the distribution number of O and Si4+ content on the growth of the SiO x layer. And the influence of the drive-in temperature of phosphorus (P) diffusion process on J 0 value is stronger than that of the deposition temperature, which was mainly related to the chemical passivation of SiO x layer induced by P-indiffusion into Si at high temperature. The reduction in the thickness of poly-Si from 110 nm to 30 nm led to an increase in the short-circuit current density (J sc) per nanometer of ∼0.0093 mA/cm2 per nm. The Poly-SEs were fabricated by 3D printing mask technology and secondary LPCVD/phosphorus diffusion with J 0, n+ ≈ 5 fA/cm2 (n+-poly-Si layer ≈ 50 nm) and J 0, metal,n++ ≈ 73.8 fA/cm2 (n++-poly-Si layer ≈ 110 nm), and the efficiency was improved by 0.12% owing to the increase in J sc value of 0.28 mA/cm2. After optimizing the passivation process, the industrial-grade TOPCon bifacial cells reached an efficiency (E ff), V oc , J sc , and FF values as high as 25.4%, 721 mV, 42.2 mA/cm2, and 83.5%, respectively. • The SiO x /n+-poly-Si layer induced parasitic absorption encountered in n-TOPCon solar cells. • Selective poly-Si based passivating contacts formed by 3D printing mask technology and secondary LPCVD/phosphorus diffusion. • The key process parameters of the SiO x layer and n+-poly-Si layers were investigated. • Cells with J 0, n+ ≈5 fA/cm2 (50 nm) and J o, metal,n++ ≈73.8 fA/cm2 (110 nm) exhibited the efficiency gain of 0.12%. • A pilot efficiency >25.4% of cells treated with optimized passivation process. [ABSTRACT FROM AUTHOR]

A high-efficiency front junction n-type passivated emitter and a rear total diffusion (n-type PERT) solar cell with the front boron diffusion passivated by a Al 2 O 3 /SiN x stack layer deposited by plasma enhanced chemical vapor method and the rear with phosphorus total diffusion and Al evaporated local contact are presented in this paper. The main purpose of this study was to develop industrially feasible front junction n-type PERT solar cells with high-efficiency; these were realized on a large area of n-type industrial 5- and 6-in. wafers. An average of 21.85% cell efficiency was achieved on 5-in. wafers, and the highest cell convert efficiency of 21.98% was achieved with V oc of 683.8 mV, J sc of 40.13 mA/cm 2 , and FF of 80.11%. For 6-in. cells, we get Fraunhofer independently confirmed efficiency of 21.49% with a V oc of 674.1 mV, a J sc of 39.77 mA/cm 2 , a FF of 80.18%. Details of cell fabrication and results are presented, followed by a best cell power loss analysis on V oc , I sc and FF . [ABSTRACT FROM AUTHOR]

• CdS surface was modified by ultrathin Si 3 N 4 layer. • A Si 3 N 4 interlayer was deposited between the Sb 2 Se 3 absorption layer and the CdS buffer layer. • The PCE of optimized device has rapidly surged from 3.57% to 5.51%. • This work is expected to pave the way for commercialised solar cells based on Sb 2 Se 3 thin films. Silicon nitride (Si 3 N 4) is essential in the preparation of silicon cells, which can increase the absorption of light and play a passivation effect. Si 3 N 4 has excellent thermal stability and chemical inertness, which can be used to improve the photoelectric performance of antimony selenide (Sb 2 Se 3) thin film solar cells. In this study, cadmium sulfide (CdS) surface formed via chemical bath deposition was modified by magnetron sputtered Si 3 N 4. The smoothed CdS surface significantly improved the fill fact and current density of the cell. The efficiency of the solar cell with a fluorine-doped tin oxide(FTO)/CdS/Si 3 N 4 (1 nm)/Sb 2 Se 3 /Au structure reached 5.51%. [ABSTRACT FROM AUTHOR]

• A small molecule hole transport materials (HTM, DFBT-PMTP) has been designed. • DFBT-PMTP canbe applied without doping and annealing in perovskites solar cells. • The efficiency of the corresponding p-i-n device reaches to as high as 21.23%. Hole transport materials (HTMs) play an important role in perovskites solar cells (Pero-SCs) which can greatly affect the stability and power conversion efficiency (PCE). While most of the efficient HTMs need doping (which results in poor stability) or the treatment of thermal annealing (which increases the complexity of the device fabrication process). In this work, we synthesized a small molecule HTM DFBT-PMTP based on 3,3′-difluoro-2,2′-bithiophene and applied it as HTM without the need for doping and thermal annealing in p-i-n Pero-SCs with the structure of ITO/HTM/MAPbI 3−x Cl x /C 60 /BCP/Ag. The PCE of the corresponding devices achieves a high value of 21.23% (19.8% for the PTAA-based reference ones), with an open-circuit voltage of 1.17 V and a high fill factor of 82.28%, which is to date among the highest values for the p-i-n MAPbI 3−x Cl x –based Pero-SCs. Interestingly, the PCE of the devices declined to 18.65 and 15.5%, while the annealing temperature of DFBT-PMTP increased to 100 and 150 °C, respectively. And the reasons for this abnormal phenomenon have been investigated including the intrisinc properties, the energy levels of MAPbI 3−x Cl x on top and the decices performance of the DFBT-PMTP films without annealing and annealed at 100 and 150 °C, respectively. The results revealed that the precise molecular structure design for the HTMs can make huge changes in the corresponding photovoltaic properties and fabrication process due to the effects on the top perovskites. [ABSTRACT FROM AUTHOR]

As a new general photovoltaic, antimony selenide (Sb 2 Se 3) thin-film solar cell is now limited by the open-circuit voltage (V oc). In this study, an ultra-thin CdS:Al film obtained by co-sputtering CdS and Al targets as a N+ layer was employed in Sb 2 Se 3 thin-film solar cells. The desposition condition of CdS:Al was optimised and solar cells with FTO/CdS:Al/CdS/Sb 2 Se 3 /Au structure were fabricated. Compared with the device without an N+ layer, the device with the N+ layer exhibited preferable photoelectric response, enlarged depletion-region width, better diode quality and reduced carrier recombination. As a result, improvements of 19% in V oc and 30% in efficiency of the Sb 2 Se 3 thin-film solar cell were realised. • High electrical concentration of CdS films has been obtained with adding Al element. • The N+/NP structure is beneficial to reduce carrier recombination and promote carrier collection. • The CdS:Al thin film as the N+ layer enhances the EQE response and improves the V oc and FF of Sb2Se3 thin film solar cells. [ABSTRACT FROM AUTHOR]

Antimony sulphide (Sb 2 S 3) thin films have attracted considerable research interest as a photovoltaic absorber material owing to their suitable band gap, large absorption coefficient, and excellent photoelectronic properties. In this study, cadmium sulphide (CdS) films were doped with potassium, which increased their crystallinity and optical transmission. These films were then used as a buffer layer to increase the efficiency of Sb 2 S 3 solar cells. Furthermore, the potassium diffused into the Sb 2 S 3 film, which increased their crystallinity and light absorption and decreased its surface roughness. Dual-functional potassium doping helped improve all of the photoelectric parameters of the Sb 2 S 3 solar cells. Specifically, the device efficiency increased from 4.57% to 6.53% (an increase of 42.89%), and a high current density of 15.29 mA cm−2 was achieved. These findings are expected to facilitate the further development of Sb 2 S 3 thin-film solar cells for industrial applications. • Potassium doped CdS films were used as a buffer layer to increase the efficiency of Sb 2 S 3 solar cells. The potassium diffused into the Sb 2 S 3 film, increased their crystallinity and light absorption and decreased its surface roughness. • Dual-functional potassium doping helped improve all of the photoelectric parameters of the Sb 2 S 3 solar cells. • Potassium doping can significantly reduce the carrier recombination in Sb 2 S 3 solar cells. • The device efficiency increased from 4.57% to 6.53% (an increase of 42.89%), and the cells delivered a high current density of 15.29 mA.cm-2 was achieved. • Cadmium sulphide (CdS) films were doped with potassium, which increased their crystallinity and optical transmission. • Doping enhance the separation of photoelectron and hole pairs, the interfacial charge transfer ability improved. [ABSTRACT FROM AUTHOR]

Organic semiconductor additives offer a promising strategy to partially eliminate defects within polycrystalline perovskite films. However, these additives are often photochemically unstable. Attempts to improve the delicate performance of perovskite solar cells (PSCs) by these additives are unimpressive. Here, we use an organic small-molecule semiconductor with unique photochemical stability, 2,9,16,23-tetra- tert -butyl-29 H ,31 H -phthalocyanine (Pc), to decorate perovskite/hole transfer layer interface. Pc molecules are observed to be located in the perovskite shallow layer and probably at perovskite grain boundaries. PSCs with moderate Pc decoration show mean and best power conversion efficiencies (PCEs) of 19.3% and 19.8%, respectively, compared to 17.5% and 18.5% for the control. The PCE decay of the best PSC with moderate Pc is less than 10% of the initial PCE, and almost 30% for the best control under 500 h continuous illumination and ambient atmosphere (~30% humidity). The photovoltaic performance enhancement induced by Pc decoration is ascribed to the decreased perovskite hole trap state density (from 2.07 × 1016 to 1.11 × 1016 cm−3), the increased perovskite hole mobility (from 7.73 × 10−3 to 1.22 × 10−2 cm2V−1s−1), improved charge carrier transfer and extraction, and partially sealed channels to impede moisture diffusion. Image 1 • A gradient phthalocyanine distribution in the shallow perovskite layer. • The phthalocyanine decoration passivates the perovskite interface and defects. • PCE and stability of perovskite solar cells are enhanced by the decoration. [ABSTRACT FROM AUTHOR]