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Title: Comparison of carrier transport mechanism under UV/Vis illumination in an AZO photodetector and an AZO/p-Si heterojunction photodiode produced by spray pyrolysis

In this study, Aluminum doped Zinc Oxide (AZO) layer is deposited on p-type silicon (p-Si) by spray pyrolysis method to fabricate ultraviolet-visible (UV/Vis) photodetector as Al doping process can have positive effect on the photodetector performance. Morphology, crystalline structure, and Al concentration of AZO layer are investigated by SEM, XRD, and EDX. The goal of this study is to analyze the mechanism of carrier transport by means of current-voltage characteristics under UV/Vis illumination in two cases: (a) electrodes connected to the surface of AZO layer and (b) electrodes connected to cross section of heterojunction (AZO/p-Si). Measurements indicate that the AZO/p-Si photodiode exhibits a higher photocurrent and lower photoresponse time under visible illumination with respect to AZO photodetector; while under UV illumination, the above result is inversed. Besides, the internal junction field of AZO/p-Si heterojunction plays an important role on this mechanism.
Authors:
; ;  [1]
  1. Department of Physics, Alzahra University, Tehran 1993893973 (Iran, Islamic Republic of)
Publication Date:
OSTI Identifier:
22412799
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 117; Journal Issue: 2; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ALUMINIUM; ALUMINIUM COMPOUNDS; COMPARATIVE EVALUATIONS; CONCENTRATION RATIO; DOPED MATERIALS; ELECTRIC CONDUCTIVITY; HETEROJUNCTIONS; ILLUMINANCE; LAYERS; PHOTODETECTORS; P-TYPE CONDUCTORS; PYROLYSIS; SCANNING ELECTRON MICROSCOPY; SILICON; SURFACES; ULTRAVIOLET RADIATION; X-RAY DIFFRACTION; ZINC OXIDES