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Title: Combinatorial sputtering of Ga-doped (Zn,Mg)O for contact applications in solar cells

Journal Article · · Solar Energy Materials and Solar Cells
 [1];  [2];  [2];  [3];  [2]
  1. National Renewable Energy Lab. (NREL), Golden, CO (United States); State Univ. of New York at Binghamton, Binghamton, NY (United States)
  2. National Renewable Energy Lab. (NREL), Golden, CO (United States)
  3. State Univ. of New York at Binghamton, Binghamton, NY (United States)

In this study, the development of tunable contact materials based on environmentally friendly chemical elements using scalable deposition approaches is necessary for existing and emerging solar energy conversion technologies. In this paper, the properties of ZnO alloyed with magnesium (Mg), and doped with gallium (Ga) are studied using combinatorial thin film experiments. As a result of these studies, the optical band gap of the sputtered Zn1-xMgxO thin films was determined to vary from 3.3 to 3.6 eV for a compositional spread of Mg content in the 0.04 < x < 0.17 range. Depending on whether or not Ga dopants were added, the electron concentrations were on the order of 1017 cm-3 or 1020 cm-3, respectively. Based on these results and on the Kelvin Probe work function measurements, a band diagram was derived using basic semiconductor physics equations. The quantitative determination of how the energy levels of Ga-doped (Zn, Mg)O thin films change as a function of Mg composition presented here, will facilitate their use as optimized contact layers for both Cu2ZnSnS4 (CZTS), Cu(In, Ga)Se2 (CIGS) and other solar cell absorbers.

Research Organization:
National Renewable Energy Laboratory (NREL), Golden, CO (United States)
Sponsoring Organization:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Solar Energy Technologies Office
Grant/Contract Number:
AC36-08GO28308
OSTI ID:
1326897
Alternate ID(s):
OSTI ID: 1359881
Report Number(s):
NREL/JA-5K00-66843
Journal Information:
Solar Energy Materials and Solar Cells, Vol. 159, Issue C; ISSN 0927-0248
Publisher:
ElsevierCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 31 works
Citation information provided by
Web of Science

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