Conductive polymer nanolayer modified one-dimensional ZnO/CdSe photoanode with enhanced photoelectrochemical properties by in-situ ions exchange method

In this paper, a ZnSe layer was formed by in-situ conversion on the surface of ZnO nanorod array, and then CdSe layer was transformed from the ZnSe layer by ion exchange method. Subsequently, a p-type poly 3,4-ethylenedioxythiophene (PEDOT) ultrathin conductive layer was deposited on the surface of CdSe by multi-current step deposition method. The separation and transmission processes of the photogenerated carriers were studied by analyzing the results of electrochemical impedance spectroscopy (EIS) and intensity modulated photocurrent/photovoltage spectroscopy (CIMPS/CIMVS). The in-situ growth method could reduce the interface barrier between ZnO and CdSe and optimize the interface exchange process of the photogenerated charge carriers. Meanwhile, the p-n junction constructed between PEDOT and CdSe layer could improve the separation efficiency of the photogenerated charge carriers. Therefore, PEDOT layer significantly promote the photoelectrochemical performance by passivating the surface state of CdSe and suppressing the secondary recombination of the photogenerated charge carriers.