Thermal activation energies of Mg in GaN:Mg measured by the Hall effect and admittance spectroscopy

2000 ◽  
Vol 88 (5) ◽  
pp. 2564-2569 ◽  
Author(s):  
D. J. Kim ◽  
D. Y. Ryu ◽  
N. A. Bojarczuk ◽  
J. Karasinski ◽  
S. Guha ◽  
...  
Keyword(s):  
Hall Effect ◽  
Thermal Activation ◽  
Activation Energies ◽  
Admittance Spectroscopy

Deep Level near EC – 0.55 eV in Undoped 4H-SiC Substrates

2006 ◽  
Vol 527-529 ◽  
pp. 505-508
Author(s):  
W.C. Mitchel ◽  
William D. Mitchell ◽  
S.R. Smith ◽  
G.R. Landis ◽  
A.O. Evwaraye ◽  
...  
Keyword(s):  
Hall Effect ◽  
Deep Level ◽  
Activation Energies ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Admittance Spectroscopy ◽  
Temperature Dependent ◽  
Thermally Stimulated Current ◽  
Commercial Grade ◽  
Transport Technique

A variety of 4H-SiC samples from undoped crystals grown by the physical vapor transport technique have been studied by temperature dependent Hall effect, optical and thermal admittance spectroscopy and thermally stimulated current. In most samples studied the activation energies were in the range 0.9 - 1.6 eV expected for commercial grade HPSI 4H-SiC. However, in several samples from developmental crystals a previously unreported deep level at EC-0.55 ± 0.01 eV was observed. Thermal admittance spectroscopy detected one level with an energy of about 0.53 eV while optical admittance spectroscopy measurements resolved two levels at 0.56 and 0.64 eV. Thermally stimulated current measurements made to study compensated levels in the material detected several peaks at energies in the range 0.2 to 0.6 eV.

Thermal Activation Energies for the Three Inequivalent Lattice Sites for the BSi Acceptor in 6H-SiC

1997 ◽  
Vol 258-263 ◽  
pp. 691-696 ◽  
Author(s):  
A.O. Evwaraye ◽  
S.R. Smith ◽  
W.C. Mitchel ◽  
H. McD. Hobgood ◽  
G. Augustine ◽  
...  
Keyword(s):  
Thermal Activation ◽  
Activation Energies

Characterization of Semi-insulating SiC

2006 ◽  
Vol 911 ◽  
Author(s):  
Nguyen Tien Son ◽  
Patrick Carlsson ◽  
Björn Magnusson ◽  
Erik Janzén
Keyword(s):  
Vapor Deposition ◽  
Thermal Activation ◽  
Deep Level ◽  
Chemical Vapor ◽  
Activation Energies ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Paramagnetic Resonance ◽  
Electron Paramagnetic

AbstractElectron paramagnetic resonance was used to study defects in high-purity semi-insulating (HPSI) substrates grown by high-temperature chemical vapor deposition and physical vapor transport. Deep level defects associated to different thermal activation energies of the resistivity ranging from ~0.6 eV to ~1.6 eV in HPSI substrates are identified and their roles in carrier compensation processes are discussed. Based on the results obtained in HPSI materials, we discuss the carrier compensation processes in vanadium-doped SI SiC substrates and different activation energies in the material.

Deep Trap Characterization In GaN Using Thermal And Optical Admittance Spectroscopy

1997 ◽  
Vol 482 ◽  
Author(s):  
A. Krtschil ◽  
H. Witte ◽  
M. Lisker ◽  
J. Christen ◽  
U. Birkle ◽  
...  
Keyword(s):  
Deep Level ◽  
Chemical Vapor ◽  
High Sensitivity ◽  
Deep Trap ◽  
Infrared Region ◽  
Activation Energies ◽  
High Resistivity ◽  
Admittance Spectroscopy ◽  
Thermal Transitions ◽  
Interface Defect

AbstractDeep defect levels and the optical as well as thermal transitions of carriers from the levels into the corresponding bands were analyzed using Thermal and Optical Admittance Spectroscopy. High resistivity GaN-layers grown by MBE and heterostructures consisting of n-type GaN-layers grown with Low Pressure Chemical Vapor Deposition on 6H-SiC substrates are investigated. In the MBE-grown GaN layers we determine deep electron traps with thermal activation energies of EA=(0.45±0.04)eV and EA=(0.65±0.03)eV. Furthermore, three different kinds of optical transitions were distinguished by Optical Admittance Spectroscopy: near band gap transitions including the transition between the valence band and a shallow donor 50meV below the conduction band, a peak at 2.1eV associated with the yellow photoluminescence band and various deep level-band transitions in the infrared region.The high sensitivity of the TAS to interface defect states was used to investigate GaN/SiC heterostructures. We found an interface defect state at 70 … 90meV. Furthermore, one level was obtained originating from the epitaxial GaN-layer having an activation energy of 63±3meV. A defect distribution was identified in the p-type SiC-substrate with activation energies between 160meV and 180meV.

Behavior of Deep Defects After Hydrogen Passivation in Znte Studied by Photoluminescence and Photoconductivity

1998 ◽  
Vol 510 ◽  
Author(s):  
S. Bhunia ◽  
D.N. Bose
Keyword(s):  
Thermal Activation ◽  
Hydrogen Plasma ◽  
Minority Carrier Lifetime ◽  
Activation Energies ◽  
Band Edge ◽  
Band Edge Emission ◽  
Hydrogen Passivation ◽  
Deep Acceptor ◽  
Strong Band ◽  
Deep Acceptor Level

AbstractThe effects of hydrogen passivation in undoped p-ZnTe single crystals were studied by photoluminescence (PL) and photoconductivity (PC) measurements. Samples were exposed to r.f hydrogen plasma at 250 °C for different durations. Before passivation PL peaks were observed at 2.06 eV, 1.47 eV, 1.33 eV and 1.06 eV. After 60 minutes exposure, samples showed strong band edge green luminescence at 2.37 eV due to an exciton bound to a Cu acceptor. Further exposure to plasma resulted in disappearance of 2.37eV and 2.34 eV peaks due to damage. In PC studies the dark current was found to decrease by a factor of 70 on 60 minutes passivation. From the temperature dependence of PC gain, the minority carrier lifetime τn, was found to go through a maximum of 4.5 × 10−7 sec at 220 K before passivation. After 60 minutes exposure, τn, remained constant at 4.5 × 10−7 sec for T > 220 K and decreased for T < 220 K. The activation energies of τn, were determined and show marked changes on passivation for T > 220 K. Comparison between PL and PC studies showed that the deep acceptor level OTe responsible for emission at 2.06 eV is passivated giving rise to strong band edge emission at 2.37 eV while emission due to the midgap impurity levels at 1.47, 1.33 and 1.05 eV remained unaffected. The thermal activation energies of the PL peaks have also been determined and allow the construction of a defect energy level diagram for ZnTe.

Activation energies of fundamental and higher order states in the fractional quantum Hall effect

1986 ◽  
Vol 170 (1-2) ◽  
pp. A223-A224
Author(s):  
G.S. Boebinger ◽  
A.M. Chang ◽  
H.L. Störmer ◽  
D.C. Tsui ◽  
J.C.M. Hwang ◽  
...  
Keyword(s):  
Hall Effect ◽  
Quantum Hall Effect ◽  
Quantum Hall ◽  
Activation Energies ◽  
Higher Order ◽  
Fractional Quantum Hall Effect ◽  
Fractional Quantum ◽  
Fractional Quantum Hall

Spectroscopic Identification of the Acceptor-Hydrogen Complex in Mg-Doped GaN Grown by MOCVD

1997 ◽  
Vol 468 ◽  
Author(s):  
W. Götz ◽  
M. D. McCluskey ◽  
N. M. Johnson ◽  
D. P. Bour ◽  
E. E. Haller
Keyword(s):  
Hall Effect ◽  
Absorption Spectra ◽  
Thermal Activation ◽  
Variable Temperature ◽  
Chemical Vapor ◽  
Thermally Activated ◽  
Local Vibrational Mode ◽  
Hall Effect Measurements ◽  
Spectroscopic Identification ◽  
Mg Doped

ABSTRACTMg-doped GaN films grown by metalorganic chemical vapor deposition were characterized by variable-temperature Hall-effect measurements and Fourier-transform infrared absorption spectroscopy. As-grown, thermally activated, and deuterated Mg-doped GaN samples were investigated. The existence of Mg-H complexes in GaN is demonstrated with the observation of a local vibrational mode (LVM) at 3125 cm-1 (8 K). At 300 K this absorption line shifts to 3122 cm-1. The intensity of the LVM line is strongest in absorption spectra of as-grown GaN. Mg which is semi-insulating. Upon thermal activation, the intensity of the LVM line significantly decreases and an acceptor concentration of 2×1019cm-3 is derived from the Hall-effect data. After deuteration at 600°C the resistivity of the Mg-doped GaN increased by four orders of magnitude. A LVM line at 2321 cm-1 (8 K) appears in the absorption spectra which is consistent with the isotopie shift of the vibrational frequency when D is substituted for H.

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