Insight into the Importance of Charge Transfer Dynamics in CsPbBr<sub>3</sub> Perovskite Nanocrystals for Photovoltaic Applications
Priyanka Dubey, Leepsa Mishra, Aradhana Panigrahi, Soumi Dutta, Ranjan Kumar Behera, Sankalan Mondal, Manas Kumar Sarangi
Abstract
Charge transfer (CT) kinetics at the interfaces of lead-halide-based perovskite nanocrystals (PNCs) are pivotal in dictating the efficacies of energy conversion. Our investigation delves into the intricacies of CT between cesium lead bromide (CsPbBr 3 )-based PNCs and fullerene (C 60 ) employing a suite of spectroscopic and theoretical investigations. Notably, we discern a facile interfacial photoinduced electron transfer (ET) from CsPbBr 3 PNCs to C 60, in good agreement with their respective aligned energy levels. Complementary current sensing atomic force microscopy measurements unveil a substantial enhancement in conductivity across the electrode–PNC–electrode nanojunction in the presence of C 60 . To establish the implications of such ET in photovoltaic devices, we have simulated the performance of two devices: one without C 60 and one with C 60 . We unfold an impressive increment in the power conversion efficiency from 12.5% to 15.8% in FTO/CsPbBr 3 /PEDOT:PSS/Au configurations upon integrating a band-aligned C 60 layer. These outcomes accentuate the relevance of regulated interlayer CT in optimizing photovoltaic device performance.