Ligand-Assisted Bulk and Interfacial Modification of Inverted Perovskite Solar Cell for Improved Stability

Perovskite-based photovoltaic technology is the most prominent and sustainable solution to cater to accelerated energy demand. For commercialization, the benchmark golden triangle criteria of cost-effectiveness, stability, and power conversion efficiency must suffice. Until now, the material has fulfilled the criteria of cost-effectiveness and efficiency but is hindered by the limitations posed due to device instability when compared to its rival counterpart, silicon solar cell technology. Herein, in this work, we have incorporated T-FA-HI ligands in bulk to improve inverted perovskite solar cell performance, mainly stability. With 1 mol % of T-FA-HI in the perovskite solution, the device's stability increased significantly compared to control devices. The device retained an efficiency of up to 85% upon light illumination for 1000 hours. The T-FA-HI ligand showed 90 % retention of the photoconversion efficiency when kept at 85 degrees C for 500 hours. The impressive performance achieved on devices with T-FA-HI ligand is attributed to the shorter chain with thiophene in the molecular structure as it accelerates the charge transportation process. In addition, it suppresses non-radiative recombination and passivates defects in the perovskites.