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A comprehensive algorithm for calculating the energy yield (EY) is used as the most important figure-of-merit in determining the capabilities of PV devices in realistic operation. The model is based on advanced optical modeling and extensive opto-thermo-electrical characterization. It takes the realistic environmental and device installation data fully into account, as well as the complete set of device specifications including all relevant temperature-induced variations. A detailed analysis and optimization of two-terminal perovskite-silicon tandem devices are done in terms of long-term electrical energy production at different geographical locations from distinct Köppen–Geiger–Photovoltaic climate zones (KGPV). It is shown that the optimal perovskite bandgap (E$_{G,PK}$) in a tandem device operating under realistic conditions is in all cases higher than the one optimized under STC, yet does not differ significantly from location to location, which is beneficial from the manufacturing point of view. The optimal E$_{G,PK}$ is influenced primarily by the spectral distribution of incident irradiance, and not so much by the operating temperature conditions. Moreover, a clear linear dependency between the optimal E$_{G,PK}$ and the weighted average photon energy of the incident irradiance is demonstrated, which presents an important rule for rapid tandem design.

We demonstrate a monolithic perovskite CIGS tandem solar cell with a certified power conversion efficiency PCE of 24.2 . The tandem solar cell still exhibits photocurrent mismatch between the subcells; thus optical simulations are used to determine the optimal device stack. Results reveal a high optical potential with the optimized device reaching a short circuit current density of 19.9 mA cm 2 and 32 PCE based on semiempirical material properties. To evaluate its energy yield, we first determine the CIGS temperature coefficient, which is at amp; 8722;0.38 K 1 notably higher than the one from the perovskite subcell amp; 8722;0.22 K 1 , favoring perovskite in the field operation at elevated cell temperatures. Both single junction cells, however, are significantly outperformed by the combined tandem device. The enhancement in energy output is more than 50 in the case of CIGS single junction device. The results demonstrate the high potential of perovskite CIGS tandem solar cells, for which we describe optical guidelines toward 30 PCE

Combining the emerging perovskite solar cell technology with existing silicon approaches in a tandem cell design offers the possibility for new low-cost high-performance devices. In this study, the potential of liquid phase crystallized silicon (LPC-Si) solar cells as a bottom cell in an all-thin-film tandem device is investigated. By optimizing the current output of a four terminal tandem using optical simulations and state-of-the-art electrical properties of the top and bottom cells, we show that an efficiency of 23.3 $\%$ can be reached, where 7.2 $\%$ are attributed to the LPC-Si bottom cell. Including the potential of future developments of both sub cells, efficiencies of over 28 $\%$ are estimated. Electrical and optical measurements of the bottom cell are performed by attaching a perovskite and a cutoff filter to the front side of the interdigitated back contacted LPC-Si cells. The measurements using a cutoff filter show a high impact of the filtered incident light spectrum on the open circuit voltage of the LPC-Si cell. A comparison of the simulated and measured absorptance shows that especially the optical properties of the transparent conductive oxides and recombination losses in the LPC-Si cause high current losses. Combining the measured data of the filtered LPC-Si cells and the semitransparent perovskite cells, yields a realistic estimation for the efficiency of a state-of-the-art four-terminal tandem device of 19.3 $\%$ .

In monolithic tandem solar cells, current voltage J V characteristics of subcells provide invaluable information about their quality and tandem operation. However, accessing the subcell J Vs is challenging and requires sophisticated spectral methods. Herein, a customized, bichromatic light emitting diode setup BCLED for in depth analysis of tandem solar cells, suitable for subcell operation analysis, and long term stability testing is presented. For this, two spectrally independent LED arrays are used to selectively bias the two subcells. The power of the developed setup is demonstrated by successfully disentangling the tandem J V curve into subcell J V curves. The method is based on a one diode model for each subcell and is validated by electrical simulations. Afterward, it is used on a fabricated 27.6 efficient perovskite silicon tandem device, resulting in great agreement with the measured J V curve. Therefore, the BCLED setup is a versatile tool, suitable for subcell characteristics and long term stability analysis of tandem solar cells

We perform rooftop testing of 6 perovskite solar cells. The devices are tracked under maximum power point and weather data is collected over several weeks. In addition, the changing irradiance and temperature conditions are also investigated under controlled laboratory conditions, where maximum power temperature coefficient of −0.17%/K is extracted. With the help of optical simulations and measured weather data, we are able to model the generated power of our devices. The temperature dependent energy yield can therefore be used to predict energy output or monitor the degradation of devices.

We show a monolithic perovskite/CIGS tandem solar cell with a certified PCE of 24.2% and a high V OC of 1.77 V, enabled by reduction of interface recombination. Using optical simulations, we further optimize the structure of the cell and compare it to perovskite/silicon tandem solar cells. The yearly energy yield of the perovskite/CIGS tandem is only 6% lower than that of the perovskite/silicon tandem, showing great potential of the perovskite/CIGS technology.

Summary Monolithic [Cs0.05(MA0.17FA0.83)0.95]Pb(I0.83Br0.17)3/Cu(In,Ga)Se2 (perovskite/CIGS) tandem solar cells promise high performance and can be processed on flexible substrates, enabling cost-efficient and ultra-lightweight space photovoltaics with power-to-weight and power-to-cost ratios surpassing those of state-of-the-art III-V semiconductor-based multijunctions. However, to become a viable space technology, the full tandem stack must withstand the harsh radiation environments in space. Here, we design tailored operando and ex situ measurements to show that perovskite/CIGS cells retain over 85% of their initial efficiency even after 68 MeV proton irradiation at a dose of 2 × 1012 p+/cm2. We use photoluminescence microscopy to show that the local quasi-Fermi-level splitting of the perovskite top cell is unaffected. We identify that the efficiency losses arise primarily from increased recombination in the CIGS bottom cell and the nickel-oxide-based recombination contact. These results are corroborated by measurements of monolithic perovskite/silicon-heterojunction cells, which severely degrade to 1% of their initial efficiency due to radiation-induced recombination centers in silicon., Graphical Abstract, Highlights • Halide perovskite sub-cells exhibit strong proton irradiation resiliency • Novel operando characterization distinguishes degradation of individual sub-cells • Perovskite/CIGS tandem solar cells retain 85% of their initial efficiency after irradiation • Perovskite/SHJ tandem solar cells degrade to 1% of their initial efficiency after irradiation, Context & Scale Monolithic perovskite/silicon and perovskite/CIGS tandem solar cells could facilitate large-scale decarbonization of the power sector, provided their long-term stability is proven. In this work, we test the stability of both technologies under high-energy proton irradiation. While this mimics the radiation environment in space, our versatile operando and ex situ methodology is also suitable for studying the long-term stability of multijunction solar cells for terrestrial applications. We find that perovskite/silicon tandem solar cells are unsuitable for space, whereas perovskite/CIGS tandems are radiation-hard, promising cheap, flexible, and ultra-lightweight space photovoltaics. Both the growing demand for smaller, cheaper satellites and the privatization of space exploration are revolutionizing space economics, providing an ideal niche for the commercialization of this new technology until the levelized cost-of-electricity can compete with current terrestrial photovoltaics., We propose and test monolithic perovskite/CIGS tandem solar cells for readily stowable, ultra-lightweight space photovoltaics. We design operando and ex situ measurements to show that perovskite/CIGS tandem solar cells retain over 85% of their initial power-conversion efficiency after high-energy proton irradiation. While the perovskite sub-cell is unaffected after this bombardment, we identify increased non-radiative recombination in the CIGS bottom cell and nickel-oxide-based recombination layer. By contrast, monolithic perovskite/silicon-heterojunction cells degrade to 1% of their initial efficiency due to radiation-induced defects in silicon.

Perovskite based tandem solar cells can increase the power conversion efficiency PCE of conventional single junction photovoltaic devices. Here, we present monolithic perovskite CIGSe tandem solar cells with a perovskite top cell fabricated directly on an as grown, rough CIGSe bottom cell. To prevent potential shunting due to the rough CIGSe surface, a thin NiOx layer is conformally deposited via atomic layer deposition on the front contact of the CIGSe bottom cell. The performance is further improved by an additional layer of the polymer PTAA at the NiOx perovskite interface. This hole transport bilayer enables a 21.6 stabilized PCE of the tandem device at amp; 8764;0.8 cm2 active area. We use TEM EDX measurements to investigate the deposition uniformity and conformality of the NiOx and PTAA layers. By absolute photoluminescence measurements, the contribution of the individual subcells to the tandem VOC is determined, revealing that further fine tuning of the recombination layers might improve the tandem VOC. Finally, on the basis of the obtained results, we give guidelines to improve monolithic perovskite CIGSe tandems toward predicted PCE estimates above 30

Metal halide perovskites show great promise to enable highly efficient and low cost tandem solar cells when being combined with silicon. Here, we combine rear junction silicon heterojunction bottom cells with p-i-n perovskite top cells into highly efficient monolithic tandem solar cells with a certified power conversion efficiency (PCE) of 25.0%. Further improvements are reached by reducing the current mismatch of the certified device. The top contact and perovskite thickness optimization allowed increasing the J SC above 19.5 mA cm -2, enabling a remarkable tandem PCE of 26.0%, however with a slightly limited fill factor (FF). To test the dependency of the FF on the current mismatch between the sub-cells, the tandems' J-V curves are measured under various illumination spectra. Interestingly, the reduced J SC in unmatched conditions is partially compensated by an enhancement of the FF. This finding is confirmed by electrical simulations based on input parameters from reference single junction devices. The simulations reveal that especially the FF in the experiment is below the expected value and show that with improved design we could reach 29% PCE for our monolithic perovskite/silicon tandem device and 31% PCE if record perovskite and silicon cell single junctions could be combined in tandem solar cells.

Highly efficient perovskite based solar cells have the potential to be a game-changing solar array technology for space applications that can be flexible, truly roll-able, ultra-lightweight and highly stowable. Outside earth's magnetic field, however, ionizing radiation causes localized defect states that accumulate and ultimately cause the failure of electronic devices. This study, assesses the radiation hardness of the widely used triple cation based perovskite absorber material, namely Cs0.05MA0.17FA0.83Pb(I0.83Br0.17)3 employing 20 and 68 MeV proton irradiation. Therefore, in situ measurements of the degradation of the proton induced current as well as the photovoltaic performance during proton irradiation are used as two independent metrics. Both measurements suggest that triple cation perovskites even exceed the radiation hardness of SiC, which is a material often proposed to possess an excellent radiation hardness. Our optimized Cs0.05MA0.17FA0.83Pb(I0.83Br0.17)3 based space solar cells reach efficiencies of 18.8% under AM0 illumination and maintain 95% of their initial efficiency even after irradiation with protons at an energy 68 MeV and a total dose of 1012 p per cm2. Degradation under 20 MeV proton irradiation is even lower. Despite the negligible impact on solar cell device performance, this study identifies that proton irradiation is changing the recombination kinetics under low excitation densities profoundly. Dark capacitance–voltage and current–voltage characteristics, photoluminescence spectra as well as photoluminescence and Voc decays are analyzed in depth. Surprisingly, two fold prolonged PL and Voc decay times are observed after proton irradiation. Often, such prolongations are attributed to a reduced charge recombination. Our kinetic model, precisely describing the observed time evolution after photoexcitation, however, establishes the prolonged release of trapped minority charge carriers from proton-radiation induced trap states.

Low-temperature atomic layer deposition (ALD) offers significant merits in terms of processing uniform, conformal and pinhole-free thin films, with sub-nanometer thickness control. In this work, plasma-assisted atomic layer deposition (ALD) of nickel oxide (NiO) is carried out by adopting bis-methylcyclopentadienyl-nickel (Ni(MeCp)2) as precursor and O2 plasma as co-reactant, over a wide table temperature range of 50–300 °C. A growth rate of 0.32 A per cycle is obtained for films deposited at 150 °C with an excellent thickness uniformity on a 4 inch silicon wafer. Bulk characteristics of the NiO film together with its interfacial properties with a triple cation hybrid perovskite absorber layer are comprehensively investigated, with the aim of integrating NiO as hole transport layer (HTL) in a p–i–n perovskite solar cell (PSC) architecture. It is concluded that “key” to efficient solar cell performance is the post-annealing treatment of the ALD NiO films in air, prior to perovskite synthesis. Post-annealing leads to better wettability of the perovskite layer and increased conductivity and mobility of the NiO films, delivering an increase in short-circuit current density (Jsc) and fill factor (FF) in the fabricated devices. Overall, a superior 17.07% PCE is achieved in the post-annealed NiO-based PSC when compared to the 13.98% PCE derived from the one with pristine NiO.

Nanostructures play an important role in state-of-the-art photovoltaic devices. Optical and electrical characteristics of the devices can be improved with properly designed and fabricated nanotextures. In this contribution, we highlight examples of possible fabrication of nanotextures by using UV nanoimprinted lithography, their optical characterization by camera based angular resolved spectroscopy and perform computer-assisted design of nanotextures for best optical performance of heterojunction silicon and ultra-thin chalcopyrite solar cells.

Laser based patterning for monolithic serial interconnection of metal halide perovskite MHP solar cells is a key process for industrial manufacturing of large scale MHP solar panels. It requires reliable patterning process parameters to achieve low interconnection losses and, thus, high efficiencies. Here, P2 laser patterning of the perovskite layer was obtained by laser ablation using conventional nanosecond laser pulses at systematically varied laser fluences. The correlation of the laser impact to the morphology, composition, and electrical functionality was analyzed in detail by several surface analytical techniques. The occurrence of laser induced periodic surface structures and microdroplets at the bottom of the trenches indicates that material removal via stress assisted ablation is strongly influenced by thermal processes. The formation of PbI 2 containing residuals was evidenced, possibly causing contact resistance losses through the P2 interconnect. These results contribute to the identification of loss factors in laser based serial interconnection of perovskite solar cells and to further process optimization for upscaling to industrial module sizes

Accurate forecasting of yearly energy yield of photovoltaic devices under realistic operating conditions is key for numerous practical applications related to further evolution of photovoltaics. In this work we present development and validation of an energy yield model applied to planar perovskite solar cells. The model is based on the combination of advanced optical modelling and extensive opto-electrical characterization and takes the geographical location and the orientation of the device into account. Using the model, we first perform a detailed sensitivity analysis and indicate the key parameters and their interdependencies that most significantly affect the calculated energy yield values. We show that the results are dominated (within 4% of the final value) by the solar irradiance dependency of the short-circuit current density, and further by the temperature dependency of the open-circuit voltage and the fill factor, whereas the irradiance dependency of the open-circuit voltage and the fill factor are mutually compensated. In the second part of the paper, we investigate how the energy yield of the device is affected by the application of external light management foils. Different texture morphologies, geographical locations, and device orientations are included in the investigation. The results show that even under realistic operating conditions, the overall trends of the light management efficiency of textured foils are not that different from those observed under standard test conditions; the highest energy yield gains in the order of 7–11% are obtained by the tetrahedral texture which is indicated as optimal in all studied cases.

Nasl. z nasl. zaslona. Opis vira z dne 21. 12. 2021. Bibliografija: str. 9-10. Abstract.

Efficient light management in monolithic perovskite/silicon tandem solar cells is one of the prerequisites for achieving high power conversion efficiencies (PCEs). Textured silicon wafers can be utilized for light management, however, this is typically not compatible with perovskite solution processing. Here, we instead employ a textured light management (LM) foil on the front-side of a tandem solar cell processed on a wafer with a planar front-side and textured back-side. This way the PCE of monolithic, 2-terminal perovskite/silicon-heterojunction tandem solar cells is significantly improved from 23.4% to 25.5%. Furthermore, we validate an advanced numerical model for our fabricated device and use it to optically optimize a number of device designs with textures at different interfaces with respect to the PCE and energy yield. These simulations predict a slightly lower optimal bandgap of the perovskite top cell in a textured device as compared to a flat one and demonstrate strong interdependency between the bandgap and the texture position in the monolithic stack. We estimate the PCE potential for the best performing both-side textured device to be 32.5% for a perovskite bandgap of 1.66 eV. Furthermore, the results show that under perpendicular illumination conditions, for optimized designs, the LM foil on top of the cell performs only slightly better than a flat anti-reflective coating. However, under diffuse illumination, the benefits of the LM foil are much greater. Finally, we calculate the energy yield for the different device designs, based on true weather data for three different locations throughout the year, taking direct as well as diffuse illumination fully into account. The results further confirm the benefits of front-side texture, even more for BIPV applications. Overall, devices built on a both-side textured silicon wafer perform best. However, we show that devices with textured LM foils on the cell's front-side are a highly efficient alternative.

Inorganic-organic perovskites like methylammonium-lead-iodide have proven to be an effective class of 17 materials for fabricating efficient solar cells. To improve their performance, light management techniques using textured surfaces, similar to those used in established solar cell technologies, should be considered. Here, we apply a light management foil created by UV nanoimprint lithography on the glass side of an inverted (p-i-n) perovskite solar cell with 16.3% efficiency. The obtained 1 mA cm(-2) increase in the short-circuit current density translates to a relative improvement in cell performance of 5%, which results in a power conversion efficiency of 17.1%. Optical 3D simulations based on experimentally obtained parameters were used to support the experimental findings. A good match between the simulated and experimental data was obtained, validating the model. Optical simulations reveal that the main improvement in device performance is due to a reduction in total reflection and that relative improvement in the short-circuit current density of up to 10% is possible for large-area devices. Therefore, our results present the potential of light management foils for improving the device performance of perovskite solar cells and pave the way for further use of optical simulations in the field of perovskite solar cells.

For methylammonium lead iodide perovskite solar cells prepared by co-evaporation, power conversion efficiencies of over 20% have been already demonstrated, however, so far, only in n-i-p configuration. Currently, the overall major challenges are the complex evaporation characteristics of organic precursors that strongly depend on the underlying charge selective contacts and the insufficient reproducibility of the co-evaporation process. To ensure a reliable co-evaporation process, it is important to identify the impact of different parameters in order to develop a more detailed understanding. In this work, we study the influence of the substrate temperature, underlying hole-transport layer (polymer PTAA versus self-assembling monolayer molecule MeO-2PACz), and perovskite precursor ratio on the morphology, composition, and performance of co-evaporated p-i-n perovskite solar cells. We first analyze the evaporation of pure precursor materials and show that the adhesion of methylammonium iodide (MAI) is significantly reduced with increased substrate temperature, while it remains almost unaffected for lead iodide (PbI

Efficiency from hole-selective contacts Perovskite/silicon tandem solar cells must stabilize a perovskite material with a wide bandgap and also maintain efficient charge carrier transport. Al-Ashouri et al. stabilized a perovskite with a 1.68–electron volt bandgap with a self-assembled monolayer that acted as an efficient hole-selective contact that minimizes nonradiative carrier recombination. In air without encapsulation, a tandem silicon cell retained 95% of its initial power conversion efficiency of 29% after 300 hours of operation. Science , this issue p. 1300

The effect of sodium doping in NiO as a contact layer for perovskite solar cells is investigated. A combined X-ray diffraction and X-ray photoelectron spectroscopy analysis reveals that Na+ mostly segregates as NaOx/NaCl species around NiO crystallites, with the effect of reducing interface capacitance as revealed by impedance spectroscopy. Inspired by this finding, the NiO/perovskite interface in perovskite solar cells is modified via insertion of an ultrathin NaCl interlayer, which increases the NiO work-function by 0.3 eV. This leads to an increase of power conversion efficiency, approaching 18%, and open-circuit voltage due to a remarkable suppression of surface recombination, as revealed by photoluminescence analysis and light intensity–dependent electrical measurements.

The rapid rise of perovskite solar cells (PSCs) is increasingly limited by the available charge-selective contacts. This work introduces two new hole-selective contacts for p–i–n PSCs that outperform all typical p-contacts in versatility, scalability and PSC power-conversion efficiency (PCE). The molecules are based on carbazole bodies with phosphonic acid anchoring groups and can form self-assembled monolayers (SAMs) on various oxides. Besides minimal material consumption and parasitic absorption, the self-assembly process enables conformal coverage of arbitrarily formed oxide surfaces with simple process control. The SAMs are designed to create an energetically aligned interface to the perovskite absorber without non-radiative losses. For three different perovskite compositions, one of which is prepared by co-evaporation, we show dopant-, additive- and interlayer-free PSCs with stabilized PCEs of up to 21.1%. Further, the conformal coverage allows to realize a monolithic CIGSe/perovskite tandem solar cell with as-deposited, rough CIGSe surface and certified efficiency of 23.26% on an active area of 1 cm2. The simplicity and diverse substrate compatibility of the SAMs might help to further progress perovskite photovoltaics towards a low-cost, widely adopted solar technology.

Perovskite/silicon tandem solar cells are the most promising concept for a future photovoltaic technology. We report on recent progress from an optical viewpoint and disucss how we achieved more than 25% device efficiency.

P2 laser patterning of the perovskite layer for serial monolithic integration was systematically investigated by laser ablation using nanosecond laser pulses at varied laser fluences. The correlation of the laser impact to the morphology, composition and electrical functionality was analyzed in detail by several surface-analytical techniques. It is found that material removal via stress-assisted ablation is strongly influenced by thermal processes. The formation of PbI 2 containing residuals was evidenced, presumably causing contact resistance losses through the P2 interconnect. From these results loss factors in laser-based serial interconnection of perovskite solar cells were identified, allowing for process optimization for upscaling to industrial module sizes.

We performed optical simulations using hydrogenated nanocrystalline silicon oxide (nc-SiOx:H) as n-doped interlayer in monolithic perovskite/c-Si heterojunction tandem solar cells. Depending on the adjustable value of its refractive index (2.0 – 2.7) and thickness, nc-SiOx:H allows to optically manage the infrared light absorption in the c-Si bottom cell minimizing reflection losses. We give guidelines for nc-SiOx:H optimization in tandem devices in combination with a systematic investigation of the effect of the surface morphology (flat or textured) on the photocurrent density. For full-flat and rear textured devices, we found matched photocurrents higher than 19 and 20 mA/cm2, respectively, using a 90 nm nc-SiOx:H interlayer with a refractive index of 2.7.

The structural phases and optoelectronic properties of coevaporated CsPbI 3 thin films with a wide range of [CsI]/[PbI 2 ] compositional ratios are investigated using high throughput experimentation and gradient samples. It is found that for CsI-rich growth conditions, CsPbI 3 can be synthesized directly at low temperature into the distorted perovskite γ-CsPbI 3 phase without detectable secondary phases. In contrast, PbI 2 -rich growth conditions are found to lead to the non-perovskite δ-phase. Photoluminescence spectroscopy and optical-pump THz-probe mapping show carrier lifetimes larger than 75 ns and charge carrier (sum) mobilities larger than 60 cm 2 V −1 s −1 for the γ-phase, indicating their suitability for high efficiency solar cells. The dependence of the carrier mobilities and luminescence peak energy on the Cs-content in the films indicates the presence of Schottky defect pairs, which may cause the stabilization of the γ-phase. Building on these results, p–i–n type solar cells with a maximum efficiency exceeding 12% and high shelf stability of more than 1200 h are demonstrated, which in the future could still be significantly improved, judging on their bulk optoelectronic properties.

The conversion efficiency of solar energy into electrical energy is the most important parameter when discussing solar cells, photovoltaic (PV) modules or PV power plants. So far many papers have been written to address the limiting efficiency of solar cells, the theoretical maximum conversion efficiency an ideal solar cell could achieve. However, most of the researches modelled sun?s spectrum as a blackbody which does not represent a realistic case. In this paper we have calculated the limiting efficiency as a function of absorbers band gap at standard test conditions using the solar spectrum AM1.5. In addition, the other key solar cells performance parameters (open-circuit voltage, short-circuit current density and fill factor) are evaluated while the intrinsic losses in the solar cells are also explained and presented in light of a cell temperature.

Device modelling and characterization are indispensable tools in the design of photovoltaic devices. In the contribution we present two challenging issues related to accurate modelling and efficient characterization of light scattering at nanotextured interfaces or other nanophotonic structures used in solar cell technologies. The model based on finite element method, which is upgraded with the Huygens’ expansion theorem is presented. It enables to calculate the angular distribution function of scattered light in the near and far field. It accounts also for the antireflection effects originating from nanoroughnesses. To characterize scattered light efficiently a camera based angular resolved spectroscopy system is presented. It captures the spatial angular distribution function in broad angular range at one shot.

The unprecedented emergence of perovskite based solar cells PSCs has been accompanied by an intensive search of suitable materials for charge selective contacts. For the first time a hole transporting self assembled monolayer SAM as the dopant free hole selective contact in p i n PSCs is used and a power conversion efficiency of up to 17.8 with average fill factor close to 80 and undetectable parasitic absorption is demonstrated. SAM formation is achieved by simply immersing the substrate into a solution of a novel mole cule V1036 that binds to the indium tin oxide surface due to its phosphonic anchoring group. The SAM and its modifications are further characterized by Fourier transform infrared and vibrational sum frequency generation spectroscopy. In addition, photoelectron spectroscopy in air is used for measuring the ionization potential of the studied SAMs. This novel approach is also suitable for achieving a conformal coverage of large area and or tex tured substrates with minimal material consumption and can potentially be extended to serve as a model system for substrate based perovskite nucleation and passivation control. Further gains in efficiency can be expected upon SAM optimization by means of molecular and compositional engineering

We present a system for the measurement of the three-dimensional (3D) angular distribution function (ADF) of scattered or emitted light using a digital camera. The 3D ADF can be determined from the digital image captured from a reflective flat screen. With the developed camera-based system we can quantify the transmitted light scattered by textured samples or the light emitted from light sources in a few second’s time. In the paper, the setup of the camera-based system is presented, the main transformations of the acquired digital image to obtain the 3D ADF are explained, and sensitivity issues are discussed. The system is applied to and validated on randomly nanotextured transparent samples and a calibrated light emitting device. Good matching is obtained with the measurements carried out with a conventional goniometric angular resolved scattering system.

A novel angular resolved scattering system for measurements of spatial angular distribution function (3D ADF) of scattered or emitted light using a digital camera is presented. 3D ADF is determined from the digital image captured from a transmissive flat screen. With the developed camera-based system we can quantify transmitted or reflected light scattered by textured samples or emitted light from light sources in a few seconds. In this paper the setup of the camera-based system is described, and the main transformations of the acquired digital image to obtain the 3D ADF are explained, along with the haze calculation. The system is applied and validated on a randomly nanotextured transparent sample and a periodically textured non-transparent sample. Good matching is obtained with rigorous simulations and measurement results carried out with a conventional goniometric angular resolved scattering system.

We present a new strategy for highly efficient perovskite/CIGSe monolithic tandem solar cells, fabricated directly on top of a rough CIGSe surface. This was enabled by conformally depositing the metal oxide NiOx by atomic layer deposition, as confirmed by TEM/EDX measurements. The resulting limiting NiOx/perovskite interface was improved by spin-coating additional thin layer of p-type polymer PTAA, thus forming a NiOx/PTAA hole selective bilayer. The fabricated tandem device has a 21.6% power conversion efficiency on 0.778 cm2, stable over 10 minutes of maximum power point tracking. The device performance is further analyzed by absolute photoluminescence measurements from which a VOC contribution of each subcell to the tandem VOC can be estimated.