Recombination and metastability in amorphous silicon and silicon germanium alloys

Technical Report · Wed Jul 01 00:00:00 EDT 1992

DOI:https://doi.org/10.2172/7042095· OSTI ID:7042095

Silver, M ^[1]

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1. North Carolina Univ., Chapel Hill, NC (United States)

This report describes the first year of a continuing research study to understand how recombination, trapping, and band-mobility modification affecting the electronic properties of amorphous semiconductors can be measured, characterized, and described by an appropriate spectrum of defect states, and how light-induced defects in a-Si:H and native defects in a-SiGe:H affect transport properties in these materials. The objective was to determine how the Staebler-Wronski defects affect the electronic processes in a-Si:H and a-SiGe:H films. To do this, electroluminescence (EL) and forward bias current in p-i-n devices (i-layer thickness > 2 {mu}m) were studied both experimentally and theoretically before and after light soaking. A simple picture was developed to compare forward bias current to the EL signal. The result was unexpected: the product of the final current times the rise time was not constant before and after light soaking as expected from the concept of gain band width, but instead changed radically. The rise time t{sub x} increased by more than one order of magnitude while the final current I{sub f} did not change significantly with light soaking. On the other hand the I{sub f}t{sub x} product did hold close to a constant when only the applied voltage changed.

• Research Organization: National Renewable Energy Lab. (NREL), Golden, CO (United States); North Carolina Univ., Chapel Hill, NC (United States)
• Sponsoring Organization: USDOE; USDOE, Washington, DC (United States)
• DOE Contract Number: AC02-83CH10093
• OSTI ID: 7042095
• Report Number(s): NREL/TP-451-4962; ON: DE92010593
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
36 MATERIALS SCIENCE
GERMANIUM ALLOYS
METASTABLE STATES
RECOMBINATION
SILICON ALLOYS
SOLAR CELLS
SEMICONDUCTOR MATERIALS
AMORPHOUS STATE
ELECTRICAL TESTING
LUMINESCENCE
PROGRESS REPORT
SEMICONDUCTOR JUNCTIONS
SILICON
SILICON SOLAR CELLS
TRAPPING
ALLOYS
DIRECT ENERGY CONVERTERS
DOCUMENT TYPES
ELEMENTS
ENERGY LEVELS
EQUIPMENT
EXCITED STATES
JUNCTIONS
MATERIALS
MATERIALS TESTING
NONDESTRUCTIVE TESTING
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
SEMIMETALS
SOLAR EQUIPMENT
TESTING
140501* - Solar Energy Conversion- Photovoltaic Conversion
360606 - Other Materials- Physical Properties- (1992-)
360602 - Other Materials- Structure & Phase Studies