Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Transient photoconductivity of a-Si:H at low temperatures induced by bandgap light

Book ·
OSTI ID:527718
; ;  [1]
  1. Univ. of Chicago, IL (United States). James Franck Inst.
The rise and decay of the photoconductivity {sigma}{sub p} of intrinsic and strongly p-type hydrogenated amorphous silicon (a-Si:H) samples was studied as a function of photocarrier generation rate G between 4.2K and 300K. In intrinsic samples the temperature regime T<60K of energy-loss hopping is clearly distinguishable from T>80K where thermal re-excitation of photocarriers is possible. For the p-type sample the temperature dividing the two regimes is near 170K. In intrinsic samples the rise of {sigma}{sub p} is faster when residual photocarriers exist from previous light exposures than when the samples are in the electronic dark equilibrium. This indicates that geminate recombination decreases with increasing photocarrier concentration. In the p-type sample the authors observe an up to 20% overshoot in the rise of {sigma}{sub p} before {sigma}{sub p} settles down to its steady state value. This overshoot increases with G. The authors interpret the overshoot as an interplay of two recombination channels with different time scales.
OSTI ID:
527718
Report Number(s):
CONF-960401--; ISBN 1-55899-323-1
Country of Publication:
United States
Language:
English