Application a-Si:H and Its Alloys for Photoreceptor Devices
Photoreceptor devices have been fabricated for positive corona with multi-layer structure of glass/ZnO /i-a-SiC:H /i-a-Si:H /p-a-SiC:H /Al type by using dual chamber plasma enhanced chemical vapor deposition (PECVD) system. 10% Silane (SiH4) and diborane (B2H6) gases diluted in hydrogen (H2) and 100% methane (CH4) gas were used as gas source. As the top passivation layer, the i-type a-SiC:H with optical band-gap of 2.93 eV was used. This highest optical band-gap was selected to allow more illumination through the photo-conductive layer. The i-type a-Si:H which has optical band-gap of 1.78 eV was used as the photo-conductive layer. The conductivity of p-type a-SiC:H films was also measured. The p-type a-SiC:H film with the lowest dark conductivity was then used as the bottom blocking layer to prevent charge injection from photo-conductive layer to the conductive electrode. The surface voltage characteristic of the device was also investigated. It decays as a function of time, with the maximum surface voltage applied is 120 volts.