Recently, considerable attention in the development of Cu 2 ZnSnS 4 (CZTS)-based thin-film solar cells has been given to the reduction of antisite defects via cation substitution. In this Letter, we report the substitution of copper atoms by silver, incorporated into the crystal lattice through a solution processable method. We observe an increase in open-circuit voltage (V OC ) by 50 mV and an accompanying rise in device efficiency from 4.9% to 7.2%. The incorporation of Ag is found to improve the grain size, enhance the depletion width of the pn-junction, and reduce the concentration of antisite defect states. This work demonstrates the promising role of Ag in reducing the V OC deficit of Cu-kesterite thin-film solar cells.

Binary compound antimony sulfide (Sb2S3) with its nontoxic and earth‐abundant constituents, is a promising light‐harvesting material for stable and high efficiency thin film photovoltaics. The intrinsic quasi‐1D (Q1D) crystal structure of Sb2S3 is known to transfer photogenerated carriers rapidly along the [hk1] orientation. However, producing Sb2S3 devices with precise control of [hk1] orientation is challenging and unfavorable crystal orientations of Sb2S3 result in severe interface and bulk recombination losses. Herein, in situ vertical growth of Sb2S3 on top of ultrathin TiO2/CdS as the electron transport layer (ETL) by a solution method is demonstrated. The planar heterojunction solar cell using [hk1]‐oriented Sb2S3 achieves a power conversion efficiency of 6.4%, performing at almost 20% higher than devices based on a [hk0]‐oriented absorber. This work opens up new prospects for pursuing high‐performance Sb2S3 thin film solar cells by tailoring the crystal orientation.

The development of high efficiency semi-transparent perovskite solar cells is necessary for application in integrated photovoltaics and tandem solar cells. However, perovskite's sensitivity to temperature and solvents impose a restriction on following processes, thus favouring physical vapor deposition for the transparent contacts. Protection may be necessary especially for high energy sputtering and a transparent buffer layer providing good electrode adhesion and conductivity is desired. Here we evaluate Ag and MoOx buffer layers in pursuit of high efficiency tandem solar cells. The usage of thin Ag as a buffer layer demonstrated Indium Tin Oxide (ITO) contacts that were resistant to delamination and yielded a 16.0% efficiency of semi-transparent perovskite solar cell with average transparency of 12% in visible range and > 50% in near infrared. Further application in tandem with Cu(In,Ga)Se showed an overall efficiency of 20.7% in a 4-terminal (4T) configuration exceeding the subcells individual efficiencies.

Owing to improvements in film morphology, crystallization process optimization, and compositional design, the power conversion efficiency of perovskite solar cells has increased from 3.8 to 22.1% in a period of 5 years. Nearly defect-free crystalline films and slow recombination rates enable polycrystalline perovskite to boast efficiencies comparable to those of multicrystalline silicon solar cells. However, volatile low melting point components and antisolvent treatments essential for the processing of dense and smooth films often lead to surface defects that hamper charge extraction. In this study, we investigate methylammonium bromide (MABr) surface treatments on perovskite films to compensate for the loss of volatile cation during the annealing process for surface defect passivation, grain growth, and a bromide-rich top layer. This facile method did not change the phase or bandgap of perovskite films yet resulted in a significant increase in the open circuit voltages of devices. The devices with 10 mM MABr treatment show 2% improvement in absolute power conversion efficiency over the control sample.

A Luminescent Solar Concentrator (LSC) greenhouse and an identical control greenhouse were constructed with photovoltaic (PV) cells attached to the roof panels of both structures. The placement and types of PV cells used in the LSC panels were varied for performance comparisons. Solar power generation was monitored continuously for one year, with leading LSC panels exhibiting a 37% increase in power production compared to the reference. The 22.3 m2 greenhouse was projected to generate a total of 1342 kWh per year, or 57.4 kWh/m2 if it were composed solely of the leading panel of Criss Cross panel design. The LSC panels showed no signs of degradation throughout the trial demonstrating the material's robustness in field conditions.