skip to main content

Title: Revealing Surface Modifications of Potassium-Fluoride-Treated Cu(In,Ga)Se 2 : A Study of Material Structure, Chemistry, and Photovoltaic Performance

The effects of alkali post-deposition treatments and device properties for polycrystalline thin film Cu(In,Ga)Se2 have been investigated. It is reported that these surface treatments lead to differences in interface chemistry and device properties. The behavior of defects in the space charge region as a function of different growth parameters is investigated by correlative analytical microscopy. The latter combines electron microscopy based imaging, Kelvin probe force microscopy, and atom probe tomography. Alkali treatments lead to copper depletion and consequent sharpening of the compositional profiles, and the measured electric potential differences of exposed Cu(In1-x,Gax)Se2 surfaces. Measurable differences in resistivity and potential have also been observed, which are expected to relate to the improved open-circuit voltage, fill-factor, and device efficiency. This study frames one perspective as to why post-deposition alkaline treatments lead to copper depletion, a mildly n-type semiconductor interface, and higher efficiency for a Cu(In,Ga)Se2 thin-film photovoltaic device.
Authors:
 [1] ;  [2] ;  [1] ;  [3] ;  [4] ;  [5] ;  [6] ;  [1]
  1. National Renewable Energy Laboratory, Golden CO 80401 USA
  2. National Renewable Energy Laboratory, Golden CO 80401 USA; Colorado School of Mines, Golden CO 80401 USA
  3. Arizona State University, Tempe AZ 85281 USA
  4. Sandia National Laboratories, Albuquerque NM 87185-0886 USA
  5. University of Tennessee-Knoxville, Knoxville TN 37996 USA
  6. Colorado School of Mines, Golden CO 80401 USA
Publication Date:
OSTI Identifier:
1324528
Report Number(s):
NREL/JA-5K00-64198
Journal ID: ISSN 2196-7350
DOE Contract Number:
AC36-08GO28308
Resource Type:
Journal Article
Resource Relation:
Journal Name: Advanced Materials Interfaces; Journal Volume: 3; Journal Issue: 17
Publisher:
Wiley-VCH
Research Org:
NREL (National Renewable Energy Laboratory (NREL), Golden, CO (United States))
Sponsoring Org:
USDOE Office of Energy Efficiency and Renewable Energy (EERE)
Country of Publication:
United States
Language:
English
Subject:
14 SOLAR ENERGY; 36 MATERIALS SCIENCE APT; CIGS; KPFM; solar cells; STEM