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Title: Hydrogenated indium oxide window layers for high-efficiency Cu(In,Ga)Se{sub 2} solar cells

High mobility hydrogenated indium oxide is investigated as a transparent contact for thin film Cu(In,Ga)Se{sub 2} (CIGS) solar cells. Hydrogen doping of In{sub 2}O{sub 3} thin films is achieved by injection of H{sub 2}O water vapor or H{sub 2} gas during the sputter process. As-deposited amorphous In{sub 2}O{sub 3}:H films exhibit a high electron mobility of ∼50 cm{sup 2}/Vs at room temperature. A bulk hydrogen concentration of ∼4 at. % was measured for both optimized H{sub 2}O and H{sub 2}-processed films, although the H{sub 2}O-derived film exhibits a doping gradient as detected by elastic recoil detection analysis. Amorphous IOH films are implemented as front contacts in CIGS based solar cells, and their performance is compared with the reference ZnO:Al electrodes. The most significant feature of IOH containing devices is an enhanced open circuit voltage (V{sub OC}) of ∼20 mV regardless of the doping approach, whereas the short circuit current and fill factor remain the same for the H{sub 2}O case or slightly decrease for H{sub 2}. The overall power conversion efficiency is improved from 15.7% to 16.2% by substituting ZnO:Al with IOH (H{sub 2}O) as front contacts. Finally, stability tests of non-encapsulated solar cells in dry air at 80 °C and constant illuminationmore » for 500 h demonstrate a higher stability for IOH-containing devices.« less
Authors:
; ; ; ; ; ; ;  [1] ;  [2]
  1. Empa – Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Thin Films and Photovoltaics, Überlandstrasse 129, 8600 Dübendorf (Switzerland)
  2. ETH Zürich, Swiss Federal Institute of Technology, Laboratory of Ion Beam Physics, Otto-Stern-Weg 5, 8093 Zürich (Switzerland)
Publication Date:
OSTI Identifier:
22410258
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 117; Journal Issue: 20; 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; COMPARATIVE EVALUATIONS; CONCENTRATION RATIO; COPPER SELENIDES; ELECTRIC POTENTIAL; ELECTRON MOBILITY; FILL FACTORS; GALLIUM SELENIDES; HYDROGEN; HYDROGENATION; INDIUM OXIDES; INDIUM SELENIDES; LAYERS; SOLAR CELLS; SPUTTERING; TEMPERATURE RANGE 0273-0400 K; THIN FILMS; WATER; WATER VAPOR