Reducing the effects of mismatch between zinc oxide and silicon by silane plasma modification

Abstract

We investigated the mismatch between zinc oxide (ZnO) and silicon (Si) upon reduction by silane plasma modification in a plasma-enhanced chemical vapor deposition system. This plasma treatment was only carried out for 10 s and the Si–H bonds that were provided by the silane plasma modification as dangling bonds on the Si wafer in addition to functioning as a conjunction layer to reduce the defects. The X-ray diffraction analysis of the ZnO/p-type silicon structure produced by silane plasma modification has a slightly lower full width at the half maximum, which improved the ZnO film’s crystalline properties. After the silane plasma modification ZnO/Si diode is produced, the measured current–voltage characteristics gave favorable rectifying properties and reverse bias had a low leakage current. The ZnO/Si diode under illumination increased the short-circuit current (Isc) from 7.32 to 19.75 mA/cm2, which is an improvement compared with a conventional bare ZnO/Si diode because of the reduced ZnO/Si interface states. Therefore, the silane plasma modification diminishes the effects of the interface and improves the ZnO/Si diode performance.