Compositional engineering solutions for decreasing trap state density and improving thermal stability in perovskite solar cells

Abstract

Perovskite solar cells need a long-term thermal stability and high efficiencies for commercial viability. Unfortunately, perovskites tend to have more defects making them vulnerable to thermal decomposition. Previous research studies have explored different strategies such as surface passivation, interfacial modification, post-treatments of perovskite films with Lewis bases and acids, and photo-curing to address the challenges due to thermal instability; however, these techniques face obstacles such as the rapid phase segregation of I⁻Br⁻ based perovskites, poor light and moisture stability, and low efficiency of devices. This review, therefore, discusses the technique of compositional engineering to suppress the defect states to improve the thermal stability of the device.