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Title: Multi-phase back contacts for CIS solar cells

Abstract

Multi-phase, single layer, non-interdiffusing M-Mo back contact metallized films, where M is selected from Cu, Ga, or mixtures thereof, for CIS cells are deposited by a sputtering process on suitable substrates, preferably glass or alumina, to prevent delamination of the CIS from the back contact layer. Typical CIS compositions include CuXSe{sub 2} where X is In or/and Ga. The multi-phase mixture is deposited on the substrate in a manner to provide a columnar microstructure, with micro-vein Cu or/and Ga regions which partially or fully vertically penetrate the entire back contact layer. The CIS semiconductor layer is then deposited by hybrid sputtering and evaporation process. The Cu/Ga-Mo deposition is controlled to produce the single layer two-phase columnar morphology with controllable Cu or Ga vein size less than about 0.01 microns in width. During the subsequent deposition of the CIS layer, the columnar Cu/Ga regions within the molybdenum of the Cu/Ga-Mo back layer tend to partially leach out, and are replaced by columns of CIS. Narrower Cu and/or Ga regions, and those with fewer inner connections between regions, leach out more slowly during the subsequent CIS deposition. This gives a good mechanical and electrical interlock of the CIS layer into the Cu/Ga-Momore » back layer. Solar cells employing In-rich CIS semiconductors bonded to the multi-phase columnar microstructure back layer of this invention exhibit vastly improved photo-electrical conversion on the order of 17% greater than Mo alone, improved uniformity of output across the face of the cell, and greater Fill Factor. 15 figs.« less

Inventors:
;
Issue Date:
Research Org.:
Midwest Research Institute, Kansas City, MO (United States); Solar Energy Research Institute; National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
170450
Patent Number(s):
5,477,088
Application Number:
PAN: 8-060,284
Assignee:
Rockett, A.A.; Yang, L.C.
DOE Contract Number:  
AC02-83CH10093
Resource Type:
Patent
Resource Relation:
Other Information: PBD: 19 Dec 1995
Country of Publication:
United States
Language:
English
Subject:
14 SOLAR ENERGY; COPPER SELENIDE SOLAR CELLS; DESIGN; FABRICATION; ELECTRIC CONTACTS; INDIUM SELENIDE SOLAR CELLS; GALLIUM SELENIDES; GRAIN SIZE; VAPOR DEPOSITED COATINGS; MOLYBDENUM; PHOTOVOLTAIC CONVERSION; ENERGY EFFICIENCY

Citation Formats

Rockett, A A, and Yang, L C. Multi-phase back contacts for CIS solar cells. United States: N. p., 1995. Web.
Rockett, A A, & Yang, L C. Multi-phase back contacts for CIS solar cells. United States.
Rockett, A A, and Yang, L C. Tue . "Multi-phase back contacts for CIS solar cells". United States.
@article{osti_170450,
title = {Multi-phase back contacts for CIS solar cells},
author = {Rockett, A A and Yang, L C},
abstractNote = {Multi-phase, single layer, non-interdiffusing M-Mo back contact metallized films, where M is selected from Cu, Ga, or mixtures thereof, for CIS cells are deposited by a sputtering process on suitable substrates, preferably glass or alumina, to prevent delamination of the CIS from the back contact layer. Typical CIS compositions include CuXSe{sub 2} where X is In or/and Ga. The multi-phase mixture is deposited on the substrate in a manner to provide a columnar microstructure, with micro-vein Cu or/and Ga regions which partially or fully vertically penetrate the entire back contact layer. The CIS semiconductor layer is then deposited by hybrid sputtering and evaporation process. The Cu/Ga-Mo deposition is controlled to produce the single layer two-phase columnar morphology with controllable Cu or Ga vein size less than about 0.01 microns in width. During the subsequent deposition of the CIS layer, the columnar Cu/Ga regions within the molybdenum of the Cu/Ga-Mo back layer tend to partially leach out, and are replaced by columns of CIS. Narrower Cu and/or Ga regions, and those with fewer inner connections between regions, leach out more slowly during the subsequent CIS deposition. This gives a good mechanical and electrical interlock of the CIS layer into the Cu/Ga-Mo back layer. Solar cells employing In-rich CIS semiconductors bonded to the multi-phase columnar microstructure back layer of this invention exhibit vastly improved photo-electrical conversion on the order of 17% greater than Mo alone, improved uniformity of output across the face of the cell, and greater Fill Factor. 15 figs.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1995},
month = {12}
}