Impact of Doping Spiro-OMeTAD with Li-TFSI, FK209, and tBP on the Performance of Perovskite Solar Cells

Abstract: This study delves into the effects of doping Spiro-OMeTAD, a widely employed hole transport material (HTM) in perovskite solar cells, with three distinct impurities: lithium bis(trifluoromethanesulfonyl)imide (Li-TFSI), FK209, and tertbutylpyridine (tBP). The focus lies on their influence on critical photovoltaic parameters, including Fill Factor (FF), power conversion efficiency (eta), short-circuit current density (Jsc), and open-circuit voltage (Voc). Employing advanced simulation tools, we systematically compare the performance of undoped and doped Spiro-OMeTAD structures. Among the examined dopants, Li-TFSI exhibits the most pronounced enhancements, significantly improving both FF and efficiency. In contrast, FK209 and tBP yield moderate gains in device performance. These results underscore the superior charge transport properties imparted by Li-TFSI doping and its capacity to optimize HTM functionality, thereby presenting a promising approach to advancing the efficiency and stability of perovskite solar cells