High-Performance Large-Area Perovskite Solar Cells Enabled by Confined Space Sublimation

Large-area devices with high power-conversion efficiency (PCE) are required for the further development of perovskite solar cells (PSCs). However, the major obstacle restricting the commercialization of large-area PSCs is the lack of reliable deposition technology for scalable perovskite thin films. Herein, a confined space sublimation method compatible with the preparation of a large-area perovskite film is introduced. First, pure PbX2 (X is I, Br, and Cl) films are exposed to CH3NH3I vapor, and the gas–solid reaction mechanisms for different lead halide layers are investigated; the perovskite films fabricated by retarded displacement between multiple halogens show large grains and a controllable band gap. Then, through mixed halogen adjustments of the PbX2 film, a maximum PCE of 20.44% (0.07 cm2) for high-efficiency PSCs with large grains (over 2.0 μm) is obtained, while the fabrication of wide-band gap PSCs with a champion PCE of 17.99% (0.07 cm2) verified the band gap-controlled compatibility of the confined space sublimation approach. Furthermore, the confined space sublimation approach is applied to fabricate large-area (6.75 cm2) devices with uniform photovoltaic performance, demonstrating the scalable potential of this approach.