Study On Preparation And Property Enhancement Of 3-Dimentional ZnO/CdTe Heterojunction Solar Cell

Photovoltaic cells and photoelectrochemical water splitting are the two main ways to solve the energy crisis using solar energy. In this paper, a new type of nanowires enhanced heterojunction solar cell has been prepared based on wide-band-gap ZnO single crystal nanowires and physical vapor deposited CdTe. In addition, we applied the P-type CdTe film to photoelectrochemical water splitting.Three-dimensional(3D) heterojunction solar cells(HSCs) were fabricated by thermal deposition of a compact CdTe layer onto ZnO nanorods(NRs). We explored the optimal thickness of ZnO NWs and the deposition temperature of CdTe, the highest short circuit current can reach 19mA/cm2.Although the 3D architecture obviously improves the short-circuit current of HSCs, the open-circuit voltage is rather low, and this problem can be solved by inserting an intermediate layer between ZnO NRs and the CdTe layer. On the basis of experimental and theoretical analyses, we found that the low open-circuit voltage mainly arose from the incomplete depletion layer and serious recombination of carriers at the CdTe/Zn O interface. The CdS intermediate layer can redistribute the depletion regions and eliminate the interface defects, thus remarkably improving the open-circuit voltage.Using thermal deposited CdTe film as a photocaathod for photoelectrochemical hydrogen production, electrophoresis deposited TiO2 as a protected layer and Pt partical as cocatalyst, we abtained good photocurrent and stability.