Improvement in the performance of AZO based MISIM photodetectors using a spray coated Al2O3 insulating layer

The present paper first time reports spray-coated aluminum oxide (Al2O3) as insulating-layer for aluminum doped zinc oxide (AZO) based metal-insulator-semiconductor-insulator-metal (MISIM) ultraviolet-photodetectors (U-PDs). Interdigited (IDT) electrodes of palladium (Pd) metal were used to fabricate Pd/Al2O3/AZO/Al2O3/Pd structured MISIM devices. The I-V characteristics of AZO based metal-semiconductor-metal (MSM) U-PDs with and without Al2O3 insulating-layer have been investigated under dark and UV-light. The MISIM devices with Al2O3 insulating-layer exhibits superior detection characteristics (with excellent contrast ratio 2971.70, higher photo current similar to 4.429 x 10(-8) and lesser dark-current similar to 1.490 x 10(-11) (at 1.65V) to those without using Al2O3 layer. Thus, the addition of Al2O3 layer in between metal (Pd) and semiconductor (AZO), may be treated as an effective approach for fabricating high performance MSM U-PDs for electronic and optoelectronic applications. (C) 2016 Elsevier GmbH. All rights reserved