Determination of the intervalley X 6 --> Gamma 6 , L 6 scattering time and the density of states effective mass of the X 7 band in GaAs by picosecond time-resolved absorption spectroscopy

1990 ◽  
Author(s):  
Wubao B. Wang ◽  
Nathan Ockman ◽  
Michael A. Cavicchia ◽  
Ming Yan ◽  
Robert R. Alfano
Keyword(s):  
Effective Mass ◽  
Density Of States ◽  
Absorption Spectroscopy ◽  
Time Resolved ◽  
Scattering Time

Comprehensive study of anomalous conduction band structure of InxGa1−xAs1-−yNy

2000 ◽  
Vol 639 ◽  
Author(s):  
C. Skierbiszewski ◽  
P. Perlin ◽  
P. Wisniewski ◽  
A. Presz ◽  
T. Suski ◽  
...  
Keyword(s):  
Dispersion Relation ◽  
Effective Mass ◽  
Conduction Band ◽  
Density Of States ◽  
Energy Gap ◽  
Free Standing ◽  
Hall Effect Measurements ◽  
High Degree ◽  
Band Anticrossing

ABSTRACTUsing free standing layer of InGaAsN we have succeeded in measuring the optical absorption in very broad spectral range (0.8-2.5eV). This gave us an insight into the conduction band density of states for the energies higher than the energy gap of this compound. By combining Hall effect measurements with determination of plasma edge frequency in infrared reflectivity for differently doped samples we were able to deduce the density of states, conduction band electrons effective mass and dispersion relation. In particular it turned out that both i) experimentally measured dispersion relation of the conduction band shows extremely high degree of nonparabolicity and consistently ii) the effective mass of electrons is few times larger than that corresponding to GaAs of the same electron concentration. So far the obtained experimental results are in line with recently proposed band anticrossing model of the electronic structure of III-N-V alloys.

The Extended State Mobility in Amorphous Silicon Alloys

1992 ◽  
Vol 258 ◽  
Author(s):  
P.M. Fauchet ◽  
R. Vanderhaghen ◽  
A. Mourchid ◽  
D. Hulin
Keyword(s):  
Amorphous Silicon ◽  
Effective Mass ◽  
Alloy Composition ◽  
Amorphous Semiconductors ◽  
Extended State ◽  
Silicon Alloys ◽  
Time Resolved ◽  
Free Carriers ◽  
Extended States ◽  
Scattering Time

ABSTRACTThe total scattering time of free carriers injected optically in the extended states of amorphous semiconductors has been measured using the techniques of femtosecond time-resolved spectroscopy. We find that this scattering time is less than 1 femtosecond, independent of alloy composition (a-Si:H, a-Si,Ge:H, a-Si,C:H) and temperature (from 77 K to 400 K). The extended state mobility deduced from the measurement of the scattering time and of the effective mass is approximately 6 cm2/Vs. A model is proposed to explain these results

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