The Polymer Society of Korea

Abstract

Doping spiro-OMeTAD has significantly contributed to enhancing the power conversion efficiency (PCE) of perovskite solar cells (PSCs). Nevertheless, the individual roles of radicals and dopants, as well as their influence on hole transport, remain poorly understood. In this study, we elucidate the distinct contributions of radicals and dopants in doped spiro-OMeTAD films through molecular dynamics simulations. To investigate the role of dopants, we analyzed the local environment of spiro-OMeTAD radicals by evaluating the coordination number and binding energy of surrounding counterions, aiming to understand how additives stabilize hole carriers. We further examined the dynamic behavior of ionic species, which materials mediate charge transport within the system. Finally, we reveal a mutualistic interaction between radicals and dopants, resulting in the formation of a percolated network in the hole transport layer, which plays a pivotal role in enabling efficient hole conduction.