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Title: Transparent Conducting ZnO Thin Films Doped with Al and Mo

Abstract

Transparent conducting oxide (TCO) thin films are a vital part of photovoltaic cells, flat-panel displays, and electrochromic windows. ZnO-based TCOs, due to the relative abundance of Zn, may reduce production costs compared to those of the prevalent TCO In2O3:Sn (ITO). Undoped ZnO, ZnO:Al (0.5, 1, and 2 wt.% Al2O3), and ZnO:Mo (2 wt.%) films were deposited by RF magnetron sputtering. Controlled incorporation of H2 in the Ar sputtering ambient increased mobility of undoped ZnO by a factor of ~20 to 48 cm2V-1s-1. H2 also appears to catalyze ionization of dopants. This enabled lightly doped ZnO:Al to provide comparable conductivity to the standard 2 wt.%-doped ZnO:Al while demonstrating reduced infrared absorption. Mo was found to be an n-type dopant of ZnO, though material properties did not match those of ZnO:Al. Scattering mechanisms were investigated using temperature-dependent Hall measurements and the method of four coefficients. This abstract is subject to government rights.

Authors:
; ; ; ;
Publication Date:
Research Org.:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy Solar Energy Technologies Program
OSTI Identifier:
1063653
DOE Contract Number:
AC36-08GO28308
Resource Type:
Conference
Resource Relation:
Conference: Bulletin of the American Physical Society; Related Information: Abstract D39.00009
Country of Publication:
United States
Language:
English
Subject:
14 SOLAR ENERGY; 36 MATERIALS SCIENCE; Solar Energy - Photovoltaics

Citation Formats

Duenow, J., Gessert, T., Wood, D., Young, D., and Coutts, T. Transparent Conducting ZnO Thin Films Doped with Al and Mo. United States: N. p., 2007. Web.
Duenow, J., Gessert, T., Wood, D., Young, D., & Coutts, T. Transparent Conducting ZnO Thin Films Doped with Al and Mo. United States.
Duenow, J., Gessert, T., Wood, D., Young, D., and Coutts, T. Mon . "Transparent Conducting ZnO Thin Films Doped with Al and Mo". United States. doi:.
@article{osti_1063653,
title = {Transparent Conducting ZnO Thin Films Doped with Al and Mo},
author = {Duenow, J. and Gessert, T. and Wood, D. and Young, D. and Coutts, T.},
abstractNote = {Transparent conducting oxide (TCO) thin films are a vital part of photovoltaic cells, flat-panel displays, and electrochromic windows. ZnO-based TCOs, due to the relative abundance of Zn, may reduce production costs compared to those of the prevalent TCO In2O3:Sn (ITO). Undoped ZnO, ZnO:Al (0.5, 1, and 2 wt.% Al2O3), and ZnO:Mo (2 wt.%) films were deposited by RF magnetron sputtering. Controlled incorporation of H2 in the Ar sputtering ambient increased mobility of undoped ZnO by a factor of ~20 to 48 cm2V-1s-1. H2 also appears to catalyze ionization of dopants. This enabled lightly doped ZnO:Al to provide comparable conductivity to the standard 2 wt.%-doped ZnO:Al while demonstrating reduced infrared absorption. Mo was found to be an n-type dopant of ZnO, though material properties did not match those of ZnO:Al. Scattering mechanisms were investigated using temperature-dependent Hall measurements and the method of four coefficients. This abstract is subject to government rights.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}

Conference:
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  • Transparent conducting Al-doped ZnO (AZO) thin films codoped with Si, or Si-codoped AZO (AZO:Si), were prepared by radio-frequency magnetron sputtering using a powder mixture of ZnO, Al{sub 2}O{sub 3}, and SiC as the target; the Si content (Si/[Si+Zn] atomic ratio) was varied from 0 to 1 at. %, but the Al content (Al/[Al+Zn] atomic ratio) was held constant. To investigate the effect of carbon on the electrical properties of AZO:Si thin films prepared using the powder targets containing SiC, the authors also prepared thin films using a mixture of ZnO, Al{sub 2}O{sub 3}, and SiO{sub 2} or SiO powders asmore » the target. They found that when AZO:Si thin films were deposited on glass substrates at about 200 degree sign C, both Al and Si doped into ZnO acted as effective donors and the atomic carbon originating from the sputtered target acted as a reducing agent. As a result, sufficient improvement was obtained in the spatial distribution of resistivity on the substrate surface in AZO:Si thin films prepared with a Si content (Si/[Si+Zn] atomic ratio) of 0.75 at. % using powder targets containing SiC. The improvement in resistivity distribution was mainly attributed to increases in both carrier concentration and Hall mobility at locations on the substrate corresponding to the target erosion region. In addition, the resistivity stability of AZO: Si thin films exposed to air for 30 min at a high temperature was found to improve with increasing Si content.« less
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