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Title: Multi-junction, monolithic solar cell using low-band-gap materials lattice matched to GaAs or Ge

Abstract

A multi-junction, monolithic, photovoltaic solar cell device is provided for converting solar radiation to photocurrent and photovoltage with improved efficiency. The solar cell device comprises a plurality of semiconductor cells, i.e., active p/n junctions, connected in tandem and deposited on a substrate fabricated from GaAs or Ge. To increase efficiency, each semiconductor cell is fabricated from a crystalline material with a lattice constant substantially equivalent to the lattice constant of the substrate material. Additionally, the semiconductor cells are selected with appropriate band gaps to efficiently create photovoltage from a larger portion of the solar spectrum. In this regard, one semiconductor cell in each embodiment of the solar cell device has a band gap between that of Ge and GaAs. To achieve desired band gaps and lattice constants, the semiconductor cells may be fabricated from a number of materials including Ge, GaInP, GaAs, GaInAsP, GaInAsN, GaAsGe, BGaInAs, (GaAs)Ge, CuInSSe, CuAsSSe, and GaInAsNP. To further increase efficiency, the thickness of each semiconductor cell is controlled to match the photocurrent generated in each cell. To facilitate photocurrent flow, a plurality of tunnel junctions of low-resistivity material are included between each adjacent semiconductor cell. The conductivity or direction of photocurrent in the solar cellmore » device may be selected by controlling the specific p-type or n-type characteristics for each active junction.« less

Inventors:
 [1];  [2];  [1]
  1. Lakewood, CO
  2. Golden, CO
Publication Date:
Research Org.:
Midwest Research Institute, Kansas City, MO (United States)
OSTI Identifier:
873957
Patent Number(s):
US 6281426
Assignee:
Midwest Research Institute (Kansas City, MO)
DOE Contract Number:  
AC36-99GO10337
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
multi-junction; monolithic; solar; cell; low-band-gap; materials; lattice; matched; gaas; photovoltaic; device; provided; converting; radiation; photocurrent; photovoltage; improved; efficiency; comprises; plurality; semiconductor; cells; active; junctions; connected; tandem; deposited; substrate; fabricated; increase; crystalline; material; constant; substantially; equivalent; additionally; selected; appropriate; band; gaps; efficiently; create; larger; portion; spectrum; regard; embodiment; gap; achieve; desired; constants; including; gainp; gainasp; gainasn; gaasge; bgainas; cuinsse; cuassse; gainasnp; thickness; controlled; match; generated; facilitate; flow; tunnel; low-resistivity; included; adjacent; conductivity; direction; controlling; specific; p-type; n-type; characteristics; junction; tunnel junctions; achieve desired; cell device; converting solar; lattice constant; crystalline material; tunnel junction; improved efficiency; lattice matched; band gap; substrate material; device comprises; solar cell; solar radiation; current flow; materials including; photovoltaic solar; substantially equivalent; solar spectrum; increase efficiency; band gaps; monolithic solar; constant substantially; /136/

Citation Formats

Olson, Jerry M, Kurtz, Sarah R, and Friedman, Daniel J. Multi-junction, monolithic solar cell using low-band-gap materials lattice matched to GaAs or Ge. United States: N. p., 2001. Web.
Olson, Jerry M, Kurtz, Sarah R, & Friedman, Daniel J. Multi-junction, monolithic solar cell using low-band-gap materials lattice matched to GaAs or Ge. United States.
Olson, Jerry M, Kurtz, Sarah R, and Friedman, Daniel J. 2001. "Multi-junction, monolithic solar cell using low-band-gap materials lattice matched to GaAs or Ge". United States. https://www.osti.gov/servlets/purl/873957.
@article{osti_873957,
title = {Multi-junction, monolithic solar cell using low-band-gap materials lattice matched to GaAs or Ge},
author = {Olson, Jerry M and Kurtz, Sarah R and Friedman, Daniel J},
abstractNote = {A multi-junction, monolithic, photovoltaic solar cell device is provided for converting solar radiation to photocurrent and photovoltage with improved efficiency. The solar cell device comprises a plurality of semiconductor cells, i.e., active p/n junctions, connected in tandem and deposited on a substrate fabricated from GaAs or Ge. To increase efficiency, each semiconductor cell is fabricated from a crystalline material with a lattice constant substantially equivalent to the lattice constant of the substrate material. Additionally, the semiconductor cells are selected with appropriate band gaps to efficiently create photovoltage from a larger portion of the solar spectrum. In this regard, one semiconductor cell in each embodiment of the solar cell device has a band gap between that of Ge and GaAs. To achieve desired band gaps and lattice constants, the semiconductor cells may be fabricated from a number of materials including Ge, GaInP, GaAs, GaInAsP, GaInAsN, GaAsGe, BGaInAs, (GaAs)Ge, CuInSSe, CuAsSSe, and GaInAsNP. To further increase efficiency, the thickness of each semiconductor cell is controlled to match the photocurrent generated in each cell. To facilitate photocurrent flow, a plurality of tunnel junctions of low-resistivity material are included between each adjacent semiconductor cell. The conductivity or direction of photocurrent in the solar cell device may be selected by controlling the specific p-type or n-type characteristics for each active junction.},
doi = {},
url = {https://www.osti.gov/biblio/873957}, journal = {},
number = ,
volume = ,
place = {United States},
year = {2001},
month = {1}
}