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Title: Ultra-violet absorption induced modifications in bulk and nanoscale electrical transport properties of Al-doped ZnO thin films

Abstract

Using conductive atomic force microscopy and Kelvin probe force microscopy, we study local electrical transport properties in aluminum-doped zinc oxide (ZnO:Al or AZO) thin films. Current mapping shows a spatial variation in conductivity which corroborates well with the local mapping of donor concentration (∼10{sup 20 }cm{sup −3}). In addition, a strong enhancement in the local current at grains is observed after exposing the film to ultra-violet (UV) light which is attributed to persistent photocurrent. Further, it is shown that UV absorption gives a smooth conduction in AZO film which in turn gives rise to an improvement in the bulk photoresponsivity of an n-AZO/p-Si heterojunction diode. This finding is in contrast to the belief that UV absorption in an AZO layer leads to an optical loss for the underneath absorbing layer of a heterojunction solar cell.

Authors:
; ;  [1]
  1. SUNAG Laboratory, Institute of Physics, Sachivalaya Marg, Bhubaneswar 751 005 (India)
Publication Date:
OSTI Identifier:
22494705
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 118; Journal Issue: 5; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 77 NANOSCIENCE AND NANOTECHNOLOGY; ALUMINIUM; ATOMIC FORCE MICROSCOPY; DOPED MATERIALS; ELECTRIC CONDUCTIVITY; HETEROJUNCTIONS; NANOSTRUCTURES; PROBES; SOLAR CELLS; SPACE DEPENDENCE; THIN FILMS; ULTRAVIOLET RADIATION; ZINC OXIDES

Citation Formats

Kumar, Mohit, Basu, Tanmoy, and Som, Tapobrata, E-mail: tsom@iopb.res.in. Ultra-violet absorption induced modifications in bulk and nanoscale electrical transport properties of Al-doped ZnO thin films. United States: N. p., 2015. Web. doi:10.1063/1.4928166.
Kumar, Mohit, Basu, Tanmoy, & Som, Tapobrata, E-mail: tsom@iopb.res.in. Ultra-violet absorption induced modifications in bulk and nanoscale electrical transport properties of Al-doped ZnO thin films. United States. doi:10.1063/1.4928166.
Kumar, Mohit, Basu, Tanmoy, and Som, Tapobrata, E-mail: tsom@iopb.res.in. 2015. "Ultra-violet absorption induced modifications in bulk and nanoscale electrical transport properties of Al-doped ZnO thin films". United States. doi:10.1063/1.4928166.
@article{osti_22494705,
title = {Ultra-violet absorption induced modifications in bulk and nanoscale electrical transport properties of Al-doped ZnO thin films},
author = {Kumar, Mohit and Basu, Tanmoy and Som, Tapobrata, E-mail: tsom@iopb.res.in},
abstractNote = {Using conductive atomic force microscopy and Kelvin probe force microscopy, we study local electrical transport properties in aluminum-doped zinc oxide (ZnO:Al or AZO) thin films. Current mapping shows a spatial variation in conductivity which corroborates well with the local mapping of donor concentration (∼10{sup 20 }cm{sup −3}). In addition, a strong enhancement in the local current at grains is observed after exposing the film to ultra-violet (UV) light which is attributed to persistent photocurrent. Further, it is shown that UV absorption gives a smooth conduction in AZO film which in turn gives rise to an improvement in the bulk photoresponsivity of an n-AZO/p-Si heterojunction diode. This finding is in contrast to the belief that UV absorption in an AZO layer leads to an optical loss for the underneath absorbing layer of a heterojunction solar cell.},
doi = {10.1063/1.4928166},
journal = {Journal of Applied Physics},
number = 5,
volume = 118,
place = {United States},
year = 2015,
month = 8
}
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