Interface passivation for 31.25%-efficient perovskite/silicon tandem solar cells

Abstract

Silicon solar cells are approaching their theoretical efficiency limit of 29%. This limitation can be exceeded with advanced device architectures, where two or more solar cells are stacked to improve the harvesting of solar energy. In this work, we devise a tandem device with a perovskite layer conformally coated on a silicon bottom cell featuring micrometric pyramids—the industry standard—to improve its photocurrent. Using an additive in the processing sequence, we regulate the perovskite crystallization process and alleviate recombination losses occurring at the perovskite top surface interfacing the electron-selective contact [buckminsterfullerene (C 60 )]. We demonstrate a device with an active area of 1.17 square centimeters, reaching a certified power conversion efficiency of 31.25%.

Surface Defect Passivation by 2-(Anthracene-9-carboxamido)ethan-1-aminium Methylammonium in Lead Iodide Mixed-Dimensional Perovskites

“…In less than two decades, metal halide perovskites have quickly risen from research obscurity to the basis of a whole new generation of photovoltaic devices, particularly as wide bandgap absorbers in tandem with silicon. − According to the national renewable research laboratory, the current record power conversion efficiency (PCE) for a single junction perovskite photovoltaic (PV) is 26.1%, and the combination of perovskite with silicon achieves a record PCE of 33.7% . This success is due to the favorable semiconducting properties of metal halide perovskites, which include tunable direct bandgaps, high absorption coefficients, low exciton binding energy, long charge carrier lifetimes, and diffusion lengths. − The direct bandgaps and high absorption coefficient of perovskites allow for thinner films of semiconducting material when compared with silicon.…”

Mitigating Iodine Diffusion by a MoO3–Organic Composite Hole Transport Layer for Stable Perovskite Solar Cells

“…Halide perovskites have demonstrated considerable promise for energy converting and light-emitting applications. − Notably, recent power conversion efficiencies (PCEs) for single-junction perovskite solar cells (PSCs) exceeding 26% place them among a few viable options for photovoltaic commercialization. − However, one major challenge is insufficient long-term stability in the presence of moisture, light, thermal stress, and applied bias, which leads to decomposition of the perovskite layer and formation of volatile species. − Among various products of perovskite decomposition, corrosive iodine species are of particular concern due to their high vapor pressure and reactivity. − The resulting iodine (I 2 ) can diffuse through adjacent transport layers and eventually corrode metal electrodes, which leads to severe and irreversible degradation of photovoltaic devices. − …”

Inorganic Framework Composition Engineering for Scalable Fabrication of Perovskite/Silicon Tandem Solar Cells

“…7,12−15 Up to now, the highest PCE for the hybrid two-step method has reached 31.25% by alleviating recombination losses at the perovskite surface interfaces by EPFL/CSEM. 16 Unfortunately, owing to the fact that the two-step method requires more elaborate regulation of the reaction process, the film quality are suboptimal compared to the one-step counterpart. 17−20 In addition, the hybrid spin-coating technique, despite its merits, is not suited for large-scale commercial fabrication, necessitat- ing the development of a hybrid evaporation blade-coating approach.…”

“…To enable the conformal growth of perovskite film on commercial textured silicon, the hybrid evaporation spin-coating two-step method was first proposed by Ballif et.al in 2018, garnering attention due to a potential short-circuit current density ( J sc ) up to over 21 mA/cm 2 . ,− Up to now, the highest PCE for the hybrid two-step method has reached 31.25% by alleviating recombination losses at the perovskite surface interfaces by EPFL/CSEM . Unfortunately, owing to the fact that the two-step method requires more elaborate regulation of the reaction process, the film quality are suboptimal compared to the one-step counterpart. − In addition, the hybrid spin-coating technique, despite its merits, is not suited for large-scale commercial fabrication, necessitating the development of a hybrid evaporation blade-coating approach.…”