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

Abstract

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

Citation Formats

Jäger, Timo, E-mail: timo.jaeger@empa.ch, Romanyuk, Yaroslav E., Nishiwaki, Shiro, Bissig, Benjamin, Pianezzi, Fabian, Fuchs, Peter, Gretener, Christina, Tiwari, Ayodhya N., and Döbeli, Max. Hydrogenated indium oxide window layers for high-efficiency Cu(In,Ga)Se{sub 2} solar cells. United States: N. p., 2015. Web. doi:10.1063/1.4921445.
Jäger, Timo, E-mail: timo.jaeger@empa.ch, Romanyuk, Yaroslav E., Nishiwaki, Shiro, Bissig, Benjamin, Pianezzi, Fabian, Fuchs, Peter, Gretener, Christina, Tiwari, Ayodhya N., & Döbeli, Max. Hydrogenated indium oxide window layers for high-efficiency Cu(In,Ga)Se{sub 2} solar cells. United States. doi:10.1063/1.4921445.
Jäger, Timo, E-mail: timo.jaeger@empa.ch, Romanyuk, Yaroslav E., Nishiwaki, Shiro, Bissig, Benjamin, Pianezzi, Fabian, Fuchs, Peter, Gretener, Christina, Tiwari, Ayodhya N., and Döbeli, Max. 2015. "Hydrogenated indium oxide window layers for high-efficiency Cu(In,Ga)Se{sub 2} solar cells". United States. doi:10.1063/1.4921445.
@article{osti_22410258,
title = {Hydrogenated indium oxide window layers for high-efficiency Cu(In,Ga)Se{sub 2} solar cells},
author = {Jäger, Timo, E-mail: timo.jaeger@empa.ch and Romanyuk, Yaroslav E. and Nishiwaki, Shiro and Bissig, Benjamin and Pianezzi, Fabian and Fuchs, Peter and Gretener, Christina and Tiwari, Ayodhya N. and Döbeli, Max},
abstractNote = {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 illumination for 500 h demonstrate a higher stability for IOH-containing devices.},
doi = {10.1063/1.4921445},
journal = {Journal of Applied Physics},
number = 20,
volume = 117,
place = {United States},
year = 2015,
month = 5
}
  • Solar cells have been fabricated by rf sputter depositing indium tin oxide onto single crystal p-type indium phosphide. Four different substrate doping densities have been used but in all cases the dopant was zinc and the wafers were <100> oriented. The optimum doping density from the range studied was 3 x 10/sup 16/ cm/sup -3/ and devices based on such substrates have yielded total area efficiencies up to 16.2% using the air mass 1.5 spectrum normalized to 100 mW cm/sup -2/, which correspond to active area efficiencies of 19.1%. A doping density less than the optimum yielded devices with excessivemore » series resistance. Higher doping densities led to a marked loss of red response.« less
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  • Solar cells based on dc magnetron sputtered indium tin oxide onto epitaxially grown films of p-InP have been fabricated and analyzed. The best cells had a global efficiency of 18.4% and an air mass zero (AMO) efficiency of 16.0%. The principal fabrication variable considered was the constituency of the sputtering gas and both argon/hydrogen and argon/oxygen mixtures have been used. The former cells have the higher efficiencies, are apparently stable, and exhibit almost ideal junction characteristics. The latter cells are relatively unstable and exhibit much higher ideality factors and reverse saturation current densities. The temperature dependence of the reverse saturationmore » current indicates totally different charge transfer mechanisms in the two cases.« less
  • Graphene oxide (GO) is becoming increasingly popular for organic electronic applications. We present large active area (0.64 cm{sup 2}), solution processable, poly[[9-(1-octylnonyl)-9H-carbazole-2,7-diyl]-2,5-thiophenediyl-2,1, 3-benzothiadiazole-4,7-diyl-2,5-thiophenediyl]:[6,6]-Phenyl C{sub 71} butyric acid methyl ester (PCDTBT:PC{sub 70}BM) organic photovoltaic (OPV) solar cells, incorporating GO hole transport layers (HTL). The power conversion efficiency (PCE) of ∼5% is the highest reported for OPV using this architecture. A comparative study of solution-processable devices has been undertaken to benchmark GO OPV performance with poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) HTL devices, confirming the viability of GO devices, with comparable PCEs, suitable as high chemical and thermal stability replacements for PEDOT:PSS in OPV.