Improving Moisture/Thermal Stability and Efficiency of CH₃NH₃PbI₃-Based Perovskite Solar Cells via Gentle Butyl Acrylate Additive Strategy

Organic–inorganic halide perovskite solar cells (PSCs) are a new class of photovoltaic devices, which have attracted increasing interests due to high efficiency, low cost, and simple fabrication process. Although a remarkable enhancement in power conversion efficiency (PCE) has been achieved in the last decade, the stability issue, including high water/heat sensitivity and UV light-induced degradation, has become one of the main obstacles for practical applications of PSCs. Herein, hydrophobic butyl acrylate with C-O and C-C groups is reported as a new additive to enhance the PCE and moisture/thermal stability of CH₃NH₃PbI₃-based PSCs, which improves the quality of the perovskite film by promoting defect passivation, constructing a suitable energy-level alignment, and increasing the charge carrier lifetime in PSCs. Such an additive is easily introduced into PSCs without the need for thermal treatment, which is typically required by other additives, causing a negative effect on the efficiency. The CH₃NH₃PbI₃-based PSC with butyl acrylate additive shows a superior PCE of 20.0%, 19% higher than that of the unmodified device (16.8%), as well as much improved moisture/thermal stability. Herein, a facile way is provided to enhance the PCE and stability of CH₃NH₃PbI₃-based PSCs simultaneously, which facilitates the commercialization of PSCs.