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Title: Effective interface state effects in hydrogenated amorphous-crystalline silicon heterostructures using ultraviolet laser photocarrier radiometry

Ultraviolet photocarrier radiometry (UV-PCR) was used for the characterization of thin-film (nanolayer) intrinsic hydrogenated amorphous silicon (i-a-Si:H) on c-Si. The small absorption depth (approximately 10 nm at 355 nm laser excitation) leads to strong influence of the nanolayer parameters on the propagation and recombination of the photocarrier density wave (CDW) within the layer and the substrate. A theoretical PCR model including the presence of effective interface carrier traps was developed and used to evaluate the transport parameters of the substrate c-Si as well as those of the i-a-Si:H nanolayer. Unlike conventional optoelectronic characterization methods such as photoconductance, photovoltage, and photoluminescence, UV-PCR can be applied to more complete quantitative characterization of a-Si:H/c-Si heterojunction solar cells, including transport properties and defect structures. The quantitative results elucidate the strong effect of a front-surface passivating nanolayer on the transport properties of the entire structure as the result of effective a-Si:H/c-Si interface trap neutralization through occupation. A further dramatic improvement of those properties with the addition of a back-surface passivating nanolayer is observed and interpreted as the result of the interaction of the increased excess bulk CDW with, and more complete occupation and neutralization of, effective front interface traps.
Authors:
 [1] ;  [1] ;  [2] ; ;  [3]
  1. Center for Advanced Diffusion-Wave Technologies (CADIFT), Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Ontario M5S 3G8 (Canada)
  2. (Canada)
  3. Electrical and Computer Engineering, University of Toronto, Toronto, Ontario M5S 3G4 (Canada)
Publication Date:
OSTI Identifier:
22267770
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 114; Journal Issue: 24; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; HYDROGENATION; LASERS; PHOTOCONDUCTIVITY; PHOTOLUMINESCENCE; POLYMERASE CHAIN REACTION; SILICON; SOLAR CELLS; ULTRAVIOLET RADIATION