Temperature Dependent Hall Measurements on CdGeAs2

1999 ◽  
Vol 607 ◽  
Author(s):  
A.J. Ptak ◽  
S. Jain ◽  
K.T Stevens ◽  
T.H. Myers ◽  
P.G. Schunemann ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Shallow Donor ◽  
Temperature Dependent ◽  
Out Of Plane ◽  
Background Doping ◽  
Apparent Variation ◽  
P Type ◽  
Matched Samples ◽  
Residual Growth

AbstractSeventeen samples of CdGeAs2 have been extensively characterized by temperature-dependent Hall effect and resistivity measurements. Due to the anisotropic nature of the electrical properties, carefully matched sample sets were fabricated with the c-axis either in or out of the plane of the sample. The matched samples allowed determination of carrier concentration and both in-plane and out-of-plane mobilities as a function of temperature. The electrical properties of both undoped and lightly doped samples were dominated by either native defects or residual growth impurities, leading to compensated p-type material. N-type doped material was obtained only with heavy doping. An apparent variation in acceptor activation energy between 110 and 165 meV could be best explained in terms of two deep acceptor levels and at least one shallow donor. Room temperature absorption coefficient data and the relation to background doping is also reported.

Temperature dependent electrical properties of rare-earth metal Er Schottky contact on p-type InP

2013 ◽  
Author(s):  
L. Dasaradha Rao ◽  
N. Ramesha Reddy ◽  
A. Ashok Kumar ◽  
V. Rajagopal Reddy
Keyword(s):  
Rare Earth ◽  
Electrical Properties ◽  
Rare Earth Metal ◽  
Schottky Contact ◽  
Earth Metal ◽  
Temperature Dependent ◽  
P Type

Electrical Properties of Defects in Ga-Doped Ge Irradiated with Fast Electrons and Protons

2015 ◽  
Vol 242 ◽  
pp. 316-321
Author(s):  
Vadim V. Emtsev ◽  
Nikolay V. Abrosimov ◽  
Vitalii V. Kozlovski ◽  
Gagik A. Oganesyan
Keyword(s):  
Electrical Properties ◽  
Point Defects ◽  
Shallow Donor ◽  
Acceptor Impurity ◽  
Impurity States ◽  
Fast Electrons ◽  
Impurity Atoms ◽  
Order Of Magnitude ◽  
Donor Acceptor ◽  
P Type

Electrical properties of radiation-produced defects in p-Ge irradiated with MeV electrons and protons are investigated. The dominant defects in electron-irradiated p-Ge were found to be neutral for the most part, whereas they are electrically active in proton-irradiated materials. Evidently, the reactions between impurity atoms and intrinsic point defects leading to formation of secondary Ga-related defects in electron-and proton-irradiated p-Ge appear to be distinct. Production rates of radiation defects in n-Ge and p-Ge are compared. A marked difference in the removal rates of shallow donor/acceptor impurity states, at least by an order-of-magnitude, is thought to be due to greatly enhanced annihilation of Frenkel pairs in p-type Ge.

Optical and Electrical Properties of Low to Highly-Degenerate InN Films

2003 ◽  
Vol 798 ◽  
Author(s):  
D. B. Haddad ◽  
H. Dai ◽  
R. Naik ◽  
C. Morgan ◽  
V. M. Naik ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Room Temperature ◽  
Energy Levels ◽  
Shallow Donor ◽  
Optical And Electrical Properties ◽  
Electrical Measurements ◽  
Temperature Dependent ◽  
Hall Effect Measurements ◽  
Lower Temperature ◽  
Different Levels

ABSTRACTThe optical and electrical properties of InN films with different levels of carrier concentrations have been investigated. Hall effect measurements at room temperature show that the InN films are n-type with carrier concentration, ne, ranging from ∼ 7 ×1017 cm-3 to ∼ 3 × 1020 cm-3 and corresponding mobility, //, of ∼ 1300 to 50 cm2V-1S-1. Optical absorption spectra of these films show a bandgap absorption edge ∼ 0.6 eV for the InN sample with the lowest ne, and 1.5 eV for the InN sample with the highest ne. However, after corrections for the degeneracy effects, all samples show an intrinsic Eg ∼ (0.60 ± 0.05) eV. Temperature dependent (5 – 600 K) electrical measurements show that ne is nearly independent of temperature below 300 K, perhaps due to the presence of donor energy levels resonating with the InN conduction band. However, all the samples show an exponential increase in ne above 300 K due to excitation of other shallow donor like sources. Mobility versus temperature graph shows a maximum ∼ 200 K for InN film with ne = 7 × 1017 cm-3 and moves towards lower temperature with increasing ne.

scholarly journals Analysis of the Visible and UV Electroluminescence in Homojunction GaN LED's

1998 ◽  
Vol 3 ◽  
Author(s):  
F. Calle ◽  
E. Monroy ◽  
F. J. Sánchez ◽  
E. Muñoz ◽  
B. Beaumont ◽  
...  
Keyword(s):  
Duty Cycle ◽  
Relaxation Times ◽  
Shallow Donor ◽  
Donor Acceptor ◽  
Level Model ◽  
High Bias ◽  
Shallow Acceptors ◽  
Current Characteristics ◽  
P Type

The electrical and electroluminescent properties of MOVPE GaN p-n homojunctions have been analyzed as a function of temperature and bias. Electroluminescence is observed for V>3 V under dc and ac conditions. The main emission at low T is a donor-acceptor transition involving shallow acceptors, though it disappears at higher T due to the ionization of the acceptors and compensation by ionized donors. Room temperature dc and ac electroluminescence spectra evolve under increasing bias from a blue-shifting visible band involving deep states at the p-type side of the p-n junction, to a band-to-band UV recombination at high bias. In agreement, the superlinear dependence of light-current characteristics at low current injection becomes linear when the defects are saturated. Time analysis of the spectra vs pulse duration and duty cycle allows the determination of the visible radiative recombination and relaxation times associated to the Mg-related deep states, which are found to behave as acceptors lying 0.55 eV above the valence band. A simple 3-level model is able to explain the visible emission, which involves the conduction band (or shallow donor) and those deep acceptors in the p-layer. Optimum UV/visible ratio emission requires intense and relatively long pulses, with a high duty cycle to impede visible recombination.

Determination of arsenic atom distribution arsenic doped silicon using HOLZ-line analysis

1996 ◽  
Vol 54 ◽  
pp. 976-977
Author(s):  
Y. Kikuchi ◽  
N. Hashikawa ◽  
F. Uesugi ◽  
E. Wakai ◽  
K. Watanabe ◽  
...  
Keyword(s):  
Inelastic Scattering ◽  
Zone Axis ◽  
Experimental Result ◽  
Background Intensity ◽  
Crystal Thickness ◽  
Arsenic Atom ◽  
Doped Silicon ◽  
P Type ◽  
Line Analysis

In order to measure the concentration of arsenic atoms in nanometer regions of arsenic doped silicon, the HOLZ analysis is carried out underthe exact [011] zone axis observation. In previous papers, it is revealed that the position of two bright lines in the outer SOLZ structures on the[011] zone axis is little influenced by the crystal thickness and the background intensity caused by inelastic scattering electrons, but is sensitive to the concentration of As atoms substitutbnal for Siatomic site.As the result, it becomes possible to determine the concentration of electrically activated As atoms in silicon within an observed area by means of the simple fitting between experimental result and dynamical simulatioan. In the present work, in order to investigate the distribution of electrically activated As in silicon, the outer HOLZ analysis is applied using a nanometer sized probe of TEM equipped with a FEG.Czodiralsld-gown<100>orientated p-type Si wafers with a resistivity of 10 Ώ cm are used for the experiments.TheAs+ implantation is performed at a dose of 5.0X1015cm-2at 25keV.

Anisotropy of Nanoindentation – a tool for the determination of nanocrystal orientation ?

2003 ◽  
Vol 779 ◽  
Author(s):  
David Christopher ◽  
Steven Kenny ◽  
Roger Smith ◽  
Asta Richter ◽  
Bodo Wolf ◽  
...  
Keyword(s):  
Crystal Surface ◽  
Scanning Force Microscopy ◽  
Depth Range ◽  
Dislocation Loops ◽  
Force Microscopy ◽  
Pile Up ◽  
Out Of Plane ◽  
Scanning Force ◽  
Dynamics Simulations

AbstractThe pile up patterns arising in nanoindentation are shown to be indicative of the sample crystal symmetry. To explain and interpret these patterns, complementary molecular dynamics simulations and experiments have been performed to determine the atomistic mechanisms of the nanoindentation process in single crystal Fe{110}. The simulations show that dislocation loops start from the tip and end on the crystal surface propagating outwards along the four in-plane <111> directions. These loops carry material away from the indenter and form bumps on the surface along these directions separated from the piled-up material around the indenter hole. Atoms also move in the two out-of-plane <111> directions causing propagation of subsurface defects and pile-up around the hole. This finding is confirmed by scanning force microscopy mapping of the imprint, the piling-up pattern proving a suitable indicator of the surface crystallography. Experimental force-depth curves over the depth range of a few nanometers do not appear smooth and show distinct pop-ins. On the sub-nanometer scale these pop-ins are also visible in the simulation curves and occur as a result of the initiation of the dislocation loops from the tip.

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