Negative Magnetoresistance in Semiconductors with Overlapping Impurity and Conduction Bands

1972 ◽  
Vol 50 (2) ◽  
pp. 165-170 ◽  
Author(s):  
J. S. Lass
Keyword(s):  
Experimental Data ◽  
Fermi Level ◽  
Conduction Band ◽  
Density Of States ◽  
Simple Function ◽  
Negative Magnetoresistance ◽  
Band Tail ◽  
Doped Semiconductors ◽  
Conduction Bands ◽  
Heavily Doped

Negative magnetoresistance observed in many heavily doped semiconductors is considered as due to a change in the population of states for which the product Δ(E) of the mobility and the density of states varies rapidly with energy. A logarithmic form of Δ(E) is found to give an excellent fit to experimental data which can thereby be described as a simple function of H/(T + θ). The form of Δ(E) suggests that the Fermi level lies in a conduction-band tail with a width of 2kθ, typically 0.2 meV for Ge and CdS. Possible repopulation mechanisms are considered.

THE HOT CARRIER TEMPERATURE IN THE ANALYSIS OF THE FREE TO ACCEPTOR PHOTOLUMINESCENCE TRANSITION

2001 ◽  
Vol 15 (17n19) ◽  
pp. 696-699 ◽  
Author(s):  
G. Fonthal ◽  
M. de los Rios ◽  
J. Quintero ◽  
N. Piraquive ◽  
H. Ariza-Calderón
Keyword(s):  
Fermi Level ◽  
Band Gap ◽  
Density Of States ◽  
Impurity Concentration ◽  
Lattice Temperature ◽  
Band Tail ◽  
Hot Carrier ◽  
Additional Information ◽  
Carrier Temperature ◽  
Shape Equation

We analyzed the free to acceptor (e-A) photoluminescence transition on a GaAs:Ge sample using the hot carrier temperature and the Kane's DOS. This latter temperature was calculated by the spectra largest energy tail. While the lattice temperature was put in the e-A Eagles' shape equation, the fitting was poor but if the modified line was put into the equation, the fitting was better. So, the ionization impurity energy, the band gap, the Fermi level and the band tail can be measured with a better precision than the measurements traditionally made with this method, Additional information about phonons participant can be obtained. In conclusion, the hot carrier temperature and the density of states due to the impurity concentration should be used in the e-A transition photoluminescence analysis.

Conduction Band-Tail Estimated from the Temperature Dependence of X1–X3Threshold Energy in Heavily-Doped n-GaP

1988 ◽  
Vol 27 (Part 1, No. 10) ◽  
pp. 1922-1928
Author(s):  
Tamio Endo ◽  
Yasushi Okino ◽  
Nobuhiko Itoh ◽  
Hiroyuki Kudo ◽  
Koichi Sugiyama
Keyword(s):  
Temperature Dependence ◽  
Conduction Band ◽  
Band Tail ◽  
Heavily Doped

The Electronic Structure of Doped Arsenic Triselenide

1985 ◽  
Vol 61 ◽  
Author(s):  
R. P. Barclay ◽  
J. M. Marshall ◽  
C. Main
Keyword(s):  
Fermi Level ◽  
Valence Band ◽  
Band Tail ◽  
Undoped Material ◽  
New Information ◽  
Arsenic Triselenide ◽  
Background Density ◽  
Heavily Doped ◽  
High Concentrations ◽  
Type Conduction

ABSTRACTWe have investigated the electronic properties of films of arsenic triselenide into which the transition metal nickel has been introduced by a co-sputtering technique. Measurement of d.c. conductivity, thermopower, optical absorption and photomobility have been performed to characterise the material. These measurements give new information concerning the influence of nickel on the optical gap, the position of the Fermi-level, and other aspects of transport in As2 Se3. In the most heavily doped sample the d.c. conductivity is increased by 11 orders of magnitude and the position of the Fermi-level is shifted by ΔEF∼0.6 eV. The results are explained in terms of a model in which an acceptor level is introduced into the valence band tail of a background density of states (DOS) obtained earlier for the undoped material. In contrast to the suggestion by previous workers that the incorporation of high concentrations of nickel can produce a transition to n-type conduction, we argue that the Fermi-level remains in the valence band tail and that hopping conduction of carriers close the Fermi-level yields a negative sign in thermopower.

Impurity-band density of states in heavily doped semiconductors: Numerical results

1982 ◽  
Vol 25 (4) ◽  
pp. 2776-2780 ◽  
Author(s):  
V. Sa-yakanit ◽  
W. Sritrakool ◽  
H. R. Glyde
Keyword(s):  
Density Of States ◽  
Impurity Band ◽  
Numerical Results ◽  
Doped Semiconductors ◽  
Heavily Doped
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