Modification engineering in carbon-based CsPbBr3 perovskite solar cells

CsPbBr 3 is an inorganic perovskite with excellent moisture, oxygen, light and thermal tolerance. The wide bandgap makes it an ideal window layer in tandem solar cells, compatible with Si, narrow-bandgap perovskites or CIGS photovoltaics. Carbon materials are potential alternatives to expensive Au/Ag electrodes in perovskite solar cells (PSCs) for practical application. The above merits of CsPbBr 3 and carbon materials have driven the rapid development of carbon-based PSCs (C-PSCs) using CsPbBr 3 light absorption layer over the last ten years. And the record power conversion efficiency (PCE) is up to 11.23%, accounting for 68% of the Shockley–Queisser (SQ) theoretical limit. This review systematically elaborates on CsPbBr 3 /carbon electrode back interface engineers for boosting the photovoltaic conversion capability of CsPbBr 3 C-PSCs, including the fabrication methods of high-quality CsPbBr 3 films (solution-processing and gas-phase), defects passivation strategies for the perovskite layers (additive engineering, buried interface and surface modification), and solutions to address the energy level mismatch in the devices. Finally, the critical challenges and prospective research directions for this kind of photovoltaic device are highlighted.