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

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 Zn 1-xMg xO 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 10 17 cm -3 or 10 20 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 Cu 2ZnSnS 4 (CZTS), Cu(In, Ga)Se 2 (CIGS) and other solar cell absorbers.
 [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)
Publication Date:
Report Number(s):
Journal ID: ISSN 0927-0248
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Solar Energy Materials and Solar Cells
Additional Journal Information:
Journal Volume: 159; Journal Issue: C; Journal ID: ISSN 0927-0248
Research Org:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Solar Energy Technologies Office (EE-4S)
Country of Publication:
United States
14 SOLAR ENERGY; 36 MATERIALS SCIENCE; transparent conductive oxide; electron affinity; high-throughput experiments; electrical contact; photovoltaic; photo-electrochemical
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1359881