Enhanced performance of perovskite solar cells with multifunctional organic interface conditioner

Regulation of interface defects and the extraction or transport of charge carriers are essential to enhance the stability and photovoltaic performance of perovskite solar cells (PSCs). A multifunctional intermediate layer of 2,7-dibromobenzo[1,2-b:6,5-b'] dithiophene-4,5-dione (DBO) is incorporated into PSCs. The small molecule of diverse functional groups facilitates intermolecular interactions that effectively mitigate the trap state, while it can form it-it stacking with 2,2 ',7,7 '-Tetrakis[N, N-di(4-methoxyphenyl)amino]-9,9 '-spirobifluorene (SpiroOMeTAD) to shorten the carrier transmission distance and expedite charge transfer. The introduction of molecular dipole moments can also change the work function (WF) and tune the energy level structure. Therefore, the optimized PSCs achieve a remarkable power conversion efficiency (PCE) of 23.43 % and demonstrate exceptional ambient stability. This study provides valuable insights for designing innovative small molecules as interface engineering, intending to further enhance device performance.