Enhancing the photovoltaic performance of inverted organic solar cells with solution-processed MoO3:PMMA anode buffer layer

Molybdenum oxide (MoO₃) is considered a promising candidate for the anode buffer layer (ABL). However, due to the mismatch in interfacial wettability, developing solution-based fabrication methods for the MoO₃ ABL presents challenges, particularly for organic solar cells (OSCs) with inverted device structures. In this work, the photoactive layer consisted of poly (3-hexylthiophene) (P3HT) as donor and (6,6)-phenyl-C61-butyric acid methyl ester (PC61BM) as acceptor used. Poly(methyl methacrylate) (PMMA) was added to the MoO3 particles dispersion for deposition of hybrid MoO3:PMMA ABL. The device structure was FTO/ZnO/P3HT:PC61BM/MoO3:PMMA/Ag. Performance evaluation, conducted under both 1000 lx white LED light (0.28 mW cm⁻2) and AM 1.5 solar simulator illumination at 100 mW/cm2, reveals that devices employing the MoO3:PMMA ABL exhibited improved power conversion efficiencies under both illumination conditions. The improvement can be attributed to enhanced light absorption, more efficient hole extraction, and reduced electron leakage current.