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.

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 valence band tail state filling in heavily doped and compensated crystals of gallium arsenide

1988 ◽  
Vol 110 (1) ◽  
pp. 221-226 ◽  
Author(s):  
D. S. Domanevskii ◽  
S. V. Zhokhovets ◽  
M. V. Prokopenya
Keyword(s):  
Gallium Arsenide ◽  
Valence Band ◽  
Band Tail ◽  
Tail State ◽  
Heavily Doped ◽  
State Filling

First-Principles Study on the Conductive Properties of P-Doped ZnO

2009 ◽  
Vol 79-82 ◽  
pp. 1253-1256 ◽  
Author(s):  
Li Guan ◽  
Qiang Li ◽  
Xu Li ◽  
Jian Xin Guo ◽  
Bo Geng ◽  
...  
Keyword(s):  
Fermi Level ◽  
Valence Band ◽  
Density Functional ◽  
Lattice Structure ◽  
Mulliken Charge ◽  
Total Density ◽  
Type Conductivity ◽  
Doped Zno ◽  
P Type ◽  
Conductive Properties

In the present paper, the lattice structure, band structure and density of state of pure and P-doped ZnO are calculated by first-principle method based on density functional theory. By analyzing the Mulliken charge overlap population and bond length, it is found that the bond of P-Zn is longer and stronger than O-Zn bond for PO-ZnO. But for PZn-ZnO, the O-P bond becomes shorter and more powerful than O-Zn bond. Also, weak O-O bonds are formed in this case. Our results show that the final total energy of PO-ZnO is lower than PZn-ZnO. The lattice structure of PO-ZnO is more stability than PZn-ZnO. For PO-ZnO, The Fermi level moves into the valence band, which expresses that the holes appear on the top of valence band and thus the PO-ZnO exhibits p-type conductivity. For PZn-ZnO, the Fermi level moves up to the conductor band and the total density of states shifts to the lower energy region, thus PZn-ZnO shows the n-type conductivity.

Sensitization of the Holes Lifetime by the Addition of Dangling Bonds in a-Si:H

2001 ◽  
Vol 664 ◽  
Author(s):  
L.F. Fonseca ◽  
S. Z. Weisz ◽  
I. Balberg
Keyword(s):  
Valence Band ◽  
Important Implication ◽  
Dangling Bond ◽  
Dangling Bonds ◽  
Defect States ◽  
Band Tail ◽  
Present Understanding

ABSTRACTThis paper is concerned with the phenomenon of the increase of the holes lifetime with the increase of the dangling bond concentration in a-Si:H. This rather surprising phenomenon that was observed, but not discussed, previously is shown to be a non-trivial effect which is based on the charged nature of the dangling bonds and a special scenario of the concentrations of the various defect states in the material. The most important implication of our study is that the charged dangling bonds can sensitize the valence band tail states, in contrast with the accepted roles of these types of states. The present understanding suggests that many new interesting phototransport phenomena can be found in a-Si:H.

POLARIZATION PROPERTIES OF SYNCHROTRON RADIATION IN THE STUDY OF ANISOTROPIC INSULATING CRYSTALS

2002 ◽  
Vol 09 (01) ◽  
pp. 469-472
Author(s):  
V. N. KOLOBANOV ◽  
I. A. KAMENSKIKH ◽  
V. V. MIKHAILIN ◽  
I. N. SHPINKOV ◽  
D. A. SPASSKY ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Optical Properties ◽  
Energy Transfer ◽  
Synchrotron Radiation ◽  
Valence Band ◽  
Conduction Band ◽  
Electronic States ◽  
Absorption Region ◽  
New Information ◽  
Fundamental Absorption Region

The optical properties of a wide series of the tungstates with the scheelite and wolframite crystal structure at the threshold of the fundamental absorption region were studied. New information about the influence of the electronic states forming the bottom of the conduction band and the top of the valence band on the formation of emission centers and mechanisms of energy transfer to these centers was obtained.

Nearly Fermi-level-pinning-free interface in metal/heavily-doped SiC Schottky structures

2021 ◽  
Vol 60 (SB) ◽  
pp. SBBD14
Author(s):  
Masahiro Hara ◽  
Mitsuaki Kaneko ◽  
Tsunenobu Kimoto
Keyword(s):  
Fermi Level ◽  
Free Interface ◽  
Fermi Level Pinning ◽  
Heavily Doped

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.

Sign in / Sign up

Export Citation Format

Share Document