Performance improvement of conjugated polymer and ZnO hybrid solar cells using nickel oxide as anode buffer layer

Abstract

AbstractThe open‐circuit voltage of hybrid solar cells based on ZnO nanoparticles (nc‐ZnO) and conjugated polymer MDMO‐PPV increased significantly by replacing poly(3,4‐ethylenedioxythiophene)‐poly(styrenesulphonate) (PEDOT:PSS) with NiOx as the anode buffer layers. The open‐circuit voltage as high as 0.828 V was obtained at high amount of ZnO (80% in weight) in the photoactive blend. Such improvement could be ascribed to the appropriate energy level of NiOx, which allows less energy loss for holes while having a sufficiently high‐conduction band minimum to function as a more efficient electron/exciton blocking layer than PEDOT:PSS. The increase of open‐circuit voltage, as well as photocurrent, resulted in a 42% improvement in power conversion efficiency. The results indicate that nickel oxide has promising potential to increase the performance of hybrid solar cells based on nc‐ZnO.