Role of band-tail carriers in metastable defect formation and annealing in hydrogenated amorphous silicon

Journal Article · Mon Jan 15 00:00:00 EST 1990 · Physical Review, B: Condensed Matter; (USA)

DOI:https://doi.org/10.1103/PhysRevB.41.1059· OSTI ID:7004969

Jackson, W B ^[1]

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1. Xerox Palo Alto Research Center, Palo Alto, California 94304 (US)

This paper presents results on annealing of carrier-induced metastable defects in hydrogenated amorphous silicon ({ital a}-Si:H) and on the dependence of the defect kinetics on carrier density. The metastable defects were studied by measuring the threshold-voltage shifts on capacitors as a function of time, temperature, and bias. The defect generation and annealing exhibit stretched-exponential-like behavior where the characteristic time for defect generation is a function of carrier density. The ratio of carrier density to defects in equilibrium are determined to be approximately 0.1, the same ratio found in doped {ital a}-Si:H. The results are consistent with dispersive hydrogen motion through an exponential distribution of barrier heights. The hopping rate and the final-state energy depend on the carrier density. This dependence on carrier density explains the carrier-, light-, and doping-induced defect formation in {ital a}-Si:H. The increase of the hopping rate due to carriers accounts for the increase in the hydrogen-diffusion rate in doped material. While much of the data are consistent with a single-hop model, the lack of correlation between generation and annealing rates indicates that defect formation occurs by multiple hopping.

• OSTI ID: 7004969
• Journal Information: Physical Review, B: Condensed Matter; (USA), Vol. 41:2; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
SILANES
CRYSTAL DEFECTS
AMORPHOUS STATE
ANNEALING
BAND THEORY
CARRIER DENSITY
CHARGE CARRIERS
FERMI LEVEL
SEMICONDUCTOR MATERIALS
TEMPERATURE EFFECTS
CRYSTAL STRUCTURE
ENERGY LEVELS
HEAT TREATMENTS
HYDRIDES
HYDROGEN COMPOUNDS
MATERIALS
ORGANIC COMPOUNDS
ORGANIC SILICON COMPOUNDS
SILICON COMPOUNDS
360602* - Other Materials- Structure & Phase Studies