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Title: Angular dependence of light trapping in In{sub 0.3}Ga{sub 0.7}As/GaAs quantum-well solar cells

The dependence of light trapping effects in In{sub 0.3}Ga{sub 0.7}As/GaAs quantum-well solar cells on wavelength and incident angle is experimentally characterized and analyzed. Separation of active device layers from their epitaxial growth substrate enables integration of thin-film semiconductor device layers with nanostructured metal/dielectric rear contacts to increase optical absorption via coupling to both Fabry-Perot resonances and guided lateral propagation modes in the semiconductor. The roles of Fabry-Perot resonances and coupling to guided modes are analyzed via photocurrent response measurements and numerical modeling for light incident at angles of 0° (normal incidence) to 30° off normal. Light trapping enables external quantum efficiency at long wavelengths as high as 2.9% per quantum well to be achieved experimentally, substantially exceeding the ∼1% per quantum well level typically observed. Increased long wavelength quantum efficiency is shown in experimental measurements to persist with increasing angle of incidence and is explained as a consequence of the large number of guided modes available in the device structure.
Authors:
; ;  [1] ; ;  [2]
  1. Microelectronics Research Center, University of Texas at Austin, 10100 Burnet Rd., Austin, Texas 78758 (United States)
  2. Clausthal Technical University, Institute of Energy Research and Physical Technologies, Clausthal (Germany)
Publication Date:
OSTI Identifier:
22275674
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 4; Other Information: (c) 2014 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; 77 NANOSCIENCE AND NANOTECHNOLOGY; ABSORPTION; COUPLING; DIELECTRIC MATERIALS; EPITAXY; GALLIUM ARSENIDES; HETEROJUNCTIONS; INCIDENCE ANGLE; INDIUM COMPOUNDS; LAYERS; QUANTUM EFFICIENCY; QUANTUM WELLS; SEMICONDUCTOR DEVICES; SEMICONDUCTOR MATERIALS; SOLAR CELLS; SUBSTRATES; THIN FILMS; TRAPPING; VISIBLE RADIATION