Dopant-Free Spiro-OMe2 Imidazole-Based Hole-Transporting Material for Stable and Low-Cost Organic–Inorganic Perovskite Solar Cell

The engineering of charge transport materials, with electronic characteristics that result in effective charge extraction and transport dynamics, is pivotal for the realization of efficient perovskite solar cells (PSCs). Herein, we elucidate the critical role of terminal substituent methoxy groups (-OCH