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

Abstract

The 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 NiO x 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 NiO x, 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. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.