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Optical Quenching of Photoconductivity in a‐Si: H Films
Author(s) -
Fuhs W.,
Welsch H. M.,
Booth D. C.
Publication year - 1983
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.2221200122
Subject(s) - photoconductivity , quenching (fluorescence) , dangling bond , impurity , sputtering , materials science , glow discharge , atomic physics , analytical chemistry (journal) , silicon , chemistry , optoelectronics , thin film , fluorescence , optics , plasma , nanotechnology , physics , organic chemistry , chromatography , quantum mechanics
Thermal and optical quenching of photoconductivity are studied in undoped a‐Si: H‐films prepared by glow discharge decomposition of silane and rf‐sputtering. It is suggested that the quenching effects arise from thermal and optical excitation of trapped minority carriers (holes) and that the amount of quenching is controlled by the density of dangling bonds, which act as recombination centers. In the glow discharge deposited films one type of quenching centers is found which is attributed to states in the valence band tail. The thermal activation energy amounts to E t ≈ 0.3 eV whereas the cut‐off‐energy in the optical quenching spectra is considerably higher, E 0 ≈ 0.65 eV. In sputtered films a second deeper set of hole traps exists possibly due to impurity contamination with energies E t ≈ 0.6 eV and E 0 ≈ 0.9 eV.