Exploring the Carrier Dynamics in Zinc Oxide–Metal Halide-Based Perovskite Nanostructures: Toward Reduced Dielectric Loss and Improved Photocurrent

Abstract

Metal halide-based perovskites have emerged as a potential candidate for optoelectronic applications because of their impressive performance achieved by tuning the optical/electrical properties through tailoring the perovskite nanostructures. Herein, we report the synthesis of composite nanostructures by incorporation of ZnO (∼6 nm) into the CsPbBr3 (CPB) perovskite framework, which shows significant enhancement of photocurrent because of efficient interfacial charge separation and reduced dielectric loss. Detailed steady-state and time-resolved photoluminescence studies have been carried out to understand charge transfer dynamics in the CsPbBr3/ZnO nanostructure composite system. Femtosecond transient absorption and broadband dielectric spectroscopy studies were carried out to determine the charge carrier relaxation and transfer mechanism. The redox energy-level diagram suggests that the photoexcited electron from the conduction band (CB) of CPB can be transferred to the CB of ZnO NP because of thermodyn...