Near-Infrared-Transparent Perovskite Solar Cells and Perovskite-Based Tandem Photovoltaics (vol 4, 2000395, 2020)

Metal halide perovskite solar cells (PSCs) have gained tremendous attention due to their high power conversion efficiencies (PCEs) and potential for low-cost manufacturing. Their wide and tunable bandgap makes perovskites an ideal candidate for tandem solar cells (TSCs) with well-established narrow bandgap photovoltaic technologies, such as crystalline silicon and Cu(In,Ga)Se-2, to boost the PCEs beyond the Shockley-Queisser limit at affordable additional cost. Although perovskite-based TSCs have shown rapid progress over the past few years, they are far from reaching their practical efficiency limit. In addition, technology commercialization needs to overcome several challenges such as processing upscalability and long-term operational stability of solar modules. In this review, a comprehensive overview of the recent progress of perovskite-based TSCs is provided and the key challenges in the field are discussed. First, the structural and optoelectronic properties of metal halide perovskite materials and preparation methods of metal halide perovskite layers are introduced. Next, the important constituents of near-infrared (NIR) transparent PSCs for achieving high efficiency along with high NIR transmittance are highlighted. Then the developments in perovskite-based TSCs are reviewed, the limiting factors are outlined, and strategies to boost the efficiencies well beyond 30% are provided. Finally, the review is concluded by highlighting the bottlenecks for commercialization and providing an outlook for technology advancement.