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Title: Electron-Selective TiO2 Contact for Cu(In,Ga)Se2 Solar Cells

Journal Article · · Scientific Reports
DOI:https://doi.org/10.1038/srep16028· OSTI ID:1256061
 [1];  [2];  [2];  [3];  [3];  [3];  [4];  [2];  [2];  [3];  [2]
  1. Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division; Industrial Technology Research Institute, Hsinchu (Taiwan). Green Energy & Environment Research Laboratorie
  2. Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division
  3. Industrial Technology Research Institute, Hsinchu (Taiwan). Green Energy & Environment Research Laboratorie
  4. Univ. of California, Berkeley, CA (United States)
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The non-toxic and wide bandgap material TiO 2 is explored as an n-type buffer layer on p-type Cu(In,Ga)Se 2 (CIGS) absorber layer for thin film solar cells. The amorphous TiO 2 thin film deposited by atomic layer deposition process at low temperatures shows conformal coverage on the CIGS absorber layer. Solar cells from non-vacuum deposited CIGS absorbers with TiO 2 buffer layer result in a high short-circuit current density of 38.9 mA/cm 2 as compared to 36.9 mA/cm 2 measured in the reference cell with CdS buffer layer, without compromising open-circuit voltage. The significant photocurrent gain, mainly in the UV part of the spectrum, can be attributed to the low parasitic absorption loss in the ultrathin TiO2 layer (~10 nm) with a larger bandgap of 3.4 eV compared to 2.4 eV of the traditionally used CdS. Overall the solar cell conversion efficiency was improved from 9.5% to 9.9% by substituting the CdS by TiO2 on an active cell area of 10.5 mm 2. Optimized TiO2 /CIGS solar cells show excellent long-term stability. The results imply that TiO2 is a promising buffer layer material for CIGS solar cells, avoiding the toxic CdS buffer layer with added performance advantage.

Research Organization:
Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
Grant/Contract Number:
AC02-05CH11231
OSTI ID:
1256061
Alternate ID(s):
OSTI ID: 1378631
Journal Information:
Scientific Reports, Vol. 5; ISSN 2045-2322
Publisher:
Nature Publishing GroupCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 47 works
Citation information provided by
Web of Science

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Cited By (4)

Functional Oxides for Photoneuromorphic Engineering: Toward a Solar Brain journal June 2019
Efficient photocatalytic degradation by a silicon solar cell module with two Schottky junction TiO 2 /Ti electrodes journal February 2018
Titanium dioxide thin films by atomic layer deposition: a review journal August 2017
Mechanochemical Solvent-Free Synthesis of Quaternary Semiconductor Cu-Fe-Sn-S Nanocrystals journal April 2017

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