Carbon-Based CsPbBr₃ Perovskite Solar Cells: All-Ambient Processes and High Thermal Stability

The device instability has been an important issue for hybrid organic-inorganic halide perovskite solar cells (PSCs). This work intends to address this issue by exploiting inorganic perovskite (CsPbBr₃) as light absorber, accompanied by replacing organic hole transport materials (HTM) and the metal electrode with a carbon electrode. All the fabrication processes (including those for CsPbBr₃ and the carbon electrode) in the PSCs are conducted in ambient atmosphere. Through a systematical optimization on the fabrication processes of CsPbBr₃ film, carbon-based PSCs (C-PSCs) obtained the highest power conversion efficiency (PCE) of about 5.0%, a relatively high value for inorganic perovskite-based PSCs. More importantly, after storage for 250 h at 80 °C, only 11.7% loss in PCE is observed for CsPbBr₃ C-PSCs, significantly lower than that for popular CH₃NH₃PbI₃ C-PSCs (59.0%) and other reported PSCs, which indicated a promising thermal stability of CsPbBr₃ C-PSCs.