Temperature Dependence of Hall Coefficient in p-type Bi2Te3 Crystals

1962 ◽  
Vol 17 (4) ◽  
pp. 727-727 ◽  
Author(s):  
Kisaburo Shogenji ◽  
Takaju Sato
Keyword(s):  
Temperature Dependence ◽  
Hall Coefficient ◽  
P Type

Anomalous Temperature Dependence of the Hall Coefficient of Heavily Al-Doped 4H-SiC Epilayers in the Band Conduction Region

2020 ◽  
Vol 1004 ◽  
pp. 215-223
Author(s):  
Hideharu Matsuura ◽  
Rinya Nishihata ◽  
Akinobu Takeshita ◽  
Kohei Ogawa ◽  
Tatsuya Imamura ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Hall Coefficient ◽  
Bipolar Transistors ◽  
Hopping Conduction ◽  
Insulated Gate Bipolar Transistors ◽  
Temperature Dependent ◽  
Anomalous Temperature ◽  
Temperature Ranges ◽  
P Type ◽  
Band Conduction

We investigate the temperature dependence of the resistivity and Hall coefficient for heavily Al-doped p-type 4H-SiC epilayers with Al concentrations (C_Al) of > 2E19 cm^−3, which are substrates for the collectors of insulated-gate bipolar transistors. The signs of the measured Hall co- efficients (R_H) changed from positive to negative at low temperatures. For epilayers with C_Al values of < 3E19 cm^−3, a negative R_H was observed in the hopping conduction region. In contrast, for epilayers with C_Al values of > 3E19 cm^−3, a negative R_H was observed in not only the hopping conduction region but also the band conduction region, which is a striking feature because the movement of free holes in the valence band should make R_H positive. For an epilayer with C_Al of 1.8E20 cm^−3, the sign of R_H clearly changed three times in the band conduction region. Moreover, the activation energies of the temperature-dependent R_H values were similar to those of the temperature-dependent resistivity in the corresponding temperature ranges, irrespective of the conduction mechanisms (band and hopping conduction).

Temperature Dependence and High-Temperature Stability of the Annealed Ni/Au Ohmic Contact to p-Type GaN in Air

2015 ◽  
Vol 45 (4) ◽  
pp. 2087-2091 ◽  
Author(s):  
Shirong Zhao ◽  
Heather McFavilen ◽  
Shuo Wang ◽  
Fernando A. Ponce ◽  
Chantal Arena ◽  
...  
Keyword(s):  
High Temperature ◽  
Temperature Dependence ◽  
Ohmic Contact ◽  
Temperature Stability ◽  
High Temperature Stability ◽  
P Type

Temperature Dependence of Photoresponse in p-Type GaAs/AlGaAs Multiple Quantum Wells: Theory and Experiment

1999 ◽  
Vol 607 ◽  
Author(s):  
F. Szmulowicz ◽  
A. Shen ◽  
H. C. Liu ◽  
G. J. Brown ◽  
Z. R. Wasilewski ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Temperature Dependence ◽  
Bound States ◽  
Light Hole ◽  
Multiple Quantum ◽  
Temperature Dependent ◽  
Long Wavelength ◽  
Hole Level ◽  
Polarization Characteristics ◽  
P Type

AbstractThis paper describes a study of the photoresponse of long-wavelength (LWIR) and mid-infrared (MWIR) p-type GaAs/AlGaAs quantum well infrared photodetectors (QWIPs) as a function of temperature and QWIP parameters. Using an 8x8 envelope-function model (EFA), we designed and calculated the optical absorption of several bound-to-continuum (BC) structures, with the optimum designs corresponding to the second light hole level (LH2) coincident with the top of the well. For the temperature-dependent study, one non-optimized LWIR and one optimized MWIR samples were grown by MBE and their photoresponse and absorption characteristics measured to test the theory. The theory shows that the placement of the LH2 resonance at the top of the well for the optimized sample and the presence of light-hole-like quasi-bound states within the heavy-hole continuum for the nonoptimized sample account for their markedly different thermal and polarization characteristics. In particular, the theory predicts that, for the LWIR sample, the LH-like quasi-bound states should lead to an increased Ppolarized photoresponse as a function of temperature. Our temperature dependent photoresponse measurements corroborate most of the theoretical findings with respect to the long-wavelength threshold, shape, and polarization and temperature dependence of the spectra.

Temperature Dependence of Metal-Semiconductor Contacts on 6H-SiC.

1995 ◽  
Vol 378 ◽  
Author(s):  
S.R. Smith ◽  
A.O. Evwaraye ◽  
W.C. Mitchel
Keyword(s):  
Temperature Dependence ◽  
Barrier Height ◽  
Semiconductor Contacts ◽  
Standard Models ◽  
P Type

AbstractWe have examined the temperature dependence of the barrier height of Au, Ag, Ni, and Al, metal-semiconductor contacts on n-type 6H-SiC, and Al metal-semiconductor contacts on p-type 6H-SiC. The barrier height was determined from the (1/C2) vs VR characteristics of the contacts at temperatures ranging from 300K to 670K. The measurements were made at 1 MHz. These measurements were compared to I-V measurements at various temperatures, and to the behavior predicted by standard models.

Vicrostructure and Electrical Properties of Kevlar/Polypyrrole Composite Fibers

1989 ◽  
Vol 175 ◽  
Author(s):  
L. P. Rector ◽  
D. DeGroot ◽  
T. J. Marks ◽  
S. H. Carr
Keyword(s):  
Electrical Conductivity ◽  
Temperature Dependence ◽  
Transport Model ◽  
Temperature Limit ◽  
Hybrid Fibers ◽  
Electrically Conducting ◽  
High Temperature Limit ◽  
Uniform Dispersion ◽  
Polypyrrole Composite ◽  
P Type

AbstractElectrically conducting composite polypyrrole/poly(p-phenyleneterephthalamide) (PPTA or KEVLAR) fibers have been prepared by chemical polymerization of pyrrole within the interstices of the hydrogen-bonded gel structure of never-dried PPTA fibers. The resultant fibers contain a uniform dispersion of polypyrrole, as evidenced by scanning electron microscopy. The temperature dependence of the electrical conductivity of these hybrid fibers is presented. The conductivity is well described by the fluctuation-induced charge transport model over the entire temperature range of interest. However, the low temperature electrical conductivity also exhibits a hoppinglike temperature dependence, and an Arrhenius-like temperature dependence is observed in the high temperature limit. Measurements of the temperaturedependent tbermopower are indicative of a p-type carrier.

Results of SIMS, LTPL and Temperature-Dependent Hall Effect Measurements Performed on Al-Doped α-SiC Substrates Grown by the M-PVT Method

2006 ◽  
Vol 527-529 ◽  
pp. 633-636 ◽  
Author(s):  
Sylvie Contreras ◽  
Marcin Zielinski ◽  
Leszek Konczewicz ◽  
Caroline Blanc ◽  
Sandrine Juillaguet ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Hall Effect ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Temperature Dependent ◽  
Large N ◽  
Hall Effect Measurements ◽  
Van Der Pauw ◽  
P Type ◽  
Made In

We report on investigation of p-type doped, SiC wafers grown by the Modified- Physical Vapor Transport (M-PVT) method. SIMS measurements give Al concentrations in the range 1018 to 1020 cm-3, with weak Ti concentration but large N compensation. To measure the wafers’ resistivity, carrier concentration and mobility, temperature-dependant Hall effect measurements have been made in the range 100-850 K using the Van der Pauw method. The temperature dependence of the mobility suggests higher Al concentration, and higher compensation, than estimated from SIMS. Additional LTPL measurements show no evidence of additional impurities in the range of investigation, but suggest that the additional compensation may come from an increased concentration of non-radiative centers.

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