Transient Infrared Stimulated Photoconductivity in a-SI:H at Low Temperatures

1995 ◽  
Vol 377 ◽  
Author(s):  
S. Heck ◽  
P. Stradins ◽  
H. Fritzsche
Keyword(s):  
Energy Loss ◽  
Amorphous Silicon ◽  
Time Resolution ◽  
Low Temperatures ◽  
Hydrogenated Amorphous Silicon ◽  
Infrared Light ◽  
Dual Beam ◽  
Tunneling Recombination ◽  
Hydrogenated Amorphous

ABSTRACTDual beam photoconductivity with bandgap primary light and hv = 0.4- 0.6eV infrared light steps was measured with Ims time resolution in hydrogenated amorphous silicon (a-Si:H) at 4.2K. The results can be described by assuming that the photocurrent transients are due to energy-loss hopping of photocarriers and that the infrared light promotes recombination by reexciting photocarriers thereby enhancing the probability of tunneling recombination.

Interaction of aluminum with hydrogenated amorphous silicon at low temperatures

1994 ◽  
Vol 75 (8) ◽  
pp. 3928-3935 ◽  
Author(s):  
M. Shahidul Haque ◽  
H. A. Naseem ◽  
W. D. Brown
Keyword(s):  
Amorphous Silicon ◽  
Low Temperatures ◽  
Hydrogenated Amorphous Silicon ◽  
Hydrogenated Amorphous

Microstructure Characterization of Amorphous Silicon Films by Effusion Measurements of Implanted Helium

2013 ◽  
Vol 1536 ◽  
pp. 175-180 ◽  
Author(s):  
W. Beyer ◽  
W. Hilgers ◽  
D. Lennartz ◽  
F.C. Maier ◽  
N.H. Nickel ◽  
...  
Keyword(s):  
Thin Film ◽  
Amorphous Silicon ◽  
Low Temperatures ◽  
Plasma Deposition ◽  
Hydrogenated Amorphous Silicon ◽  
Silicon Films ◽  
Hot Wire ◽  
Common Features ◽  
Hydrogenated Amorphous

ABSTRACTAn important property of thin film silicon and related materials is the microstructure which may involve the presence of interconnected and isolated voids. We report on effusion measurements of implanted helium (He) to detect such voids. Several series of hydrogenated and unhydrogenated amorphous silicon films prepared by the methods of plasma deposition, hot wire deposition and vacuum evaporation were investigated. The results show common features like a He effusion peak at low temperatures attributed to He out-diffusion through a compact material or through interconnected voids, and a He effusion peak at high temperatures attributed to He trapped in isolated voids. While undoped plasma-grown device-grade hydrogenated amorphous silicon (a-Si:H) films show a rather low concentration of such isolated voids, its concentration can be rather high in doped a-Si:H, in unhydrogenated evaporated material and others.

Trapping in hydrogenated amorphous silicon studied by dual-beam modulated photoconductivity

1989 ◽  
Vol 59 (6) ◽  
pp. 681-689 ◽  
Author(s):  
J. Bullot ◽  
P. Cordier ◽  
M. Gauthier ◽  
G. Mawawa
Keyword(s):  
Amorphous Silicon ◽  
Hydrogenated Amorphous Silicon ◽  
Dual Beam ◽  
Hydrogenated Amorphous

Transient Photoconductivity of a-Si:H at Low Temperatures Induced by Bandgap Light

1996 ◽  
Vol 420 ◽  
Author(s):  
S. Heck ◽  
P. Stradins ◽  
H. Fritzsche
Keyword(s):  
Steady State ◽  
Energy Loss ◽  
Low Temperatures ◽  
Hydrogenated Amorphous Silicon ◽  
Geminate Recombination ◽  
Transient Photoconductivity ◽  
P Type ◽  
Hydrogenated Amorphous ◽  
Different Time Scales ◽  
Type Sample

AbstractThe rise and decay of the photoconductivity σp 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 σp 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 we observe an up to 20 percent overshoot in the rise of σp before σp settles down to its steady state value. This overshoot increases with G. We interpret the overshoot as an interplay of two recombination channels with different time scales.

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