Al doped ZnO based metal-semiconductor-metal and metal-insulator-semiconductor-insulator-metal UV sensors

The paper reports the fabrication and characterization of Al doped ZnO (Al:ZnO) based metal-semiconductor-metal (MSM) and metal-insulator-semiconductor-insulator-metal (MISIM) ultraviolet sensors (Ss). The Al:ZnO thin film was grown on a p-type Si substrates by RF-sputtering method and palladium (Pd) was used as interdigitated metal electrodes for the MSM and MISIM devices. Approximately 5 nm thick layer of SiO2 were deposited above Al:ZnO thin film for MISIM devices. The I-V characteristics of MSM and MISIM devices with finger-spacing of 5 μm were measured under dark and under ultraviolet (UV) light. It was found that Iphoto/Idark values were 0.893 × 102 and 1.735 × 103 also the measured responsivities were 0.0411 and 0.0155 A/W for MSM and MISIM UV sensors (UVSs), respectively. These devices can find applications in various electronic and optoelectronic systems.