scholarly journals The transformations of the EL6 deep level defect in n-GaAs: Is EL6 a DX-like center?

1998 ◽  
Vol 510 ◽  
Author(s):  
C.V. Reddy ◽  
S. Fung ◽  
C.D. Beling
Keyword(s):  
Deep Level ◽  
Lattice Relaxation ◽  
Persistent Photoconductivity ◽  
Charge Redistribution ◽  
Deep Level Defect ◽  
Native Defects ◽  
Large Lattice ◽  
Dx Center ◽  
Low Temperature Grown Gaas ◽  
Redistribution Effect

AbstractBased on the charge redistribution effect, as observed by the present authors, and the earlier reported large lattice relaxation and persistent photoconductivity phenomena associated with the EL6 defect seen in doped, undoped, semiinsulating(SI) and low temperature grown GaAs LT-GaAs), it is suggested that this defect be classified as a DX-center. A tentative unified atomic model is proposed for all the native defects EL2, EL3, EL5, and EL6 observed in GaAs.

scholarly journals Chemical trends of deep levels in van der Waals semiconductors

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Penghong Ci ◽  
Xuezeng Tian ◽  
Jun Kang ◽  
Anthony Salazar ◽  
Kazutaka Eriguchi ◽  
...  
Keyword(s):  
Deep Level ◽  
Energy Levels ◽  
Van Der Waals ◽  
Deep Levels ◽  
Persistent Photoconductivity ◽  
Sulfur Vacancy ◽  
Native Defects ◽  
Crystal Imperfections ◽  
Dx Center ◽  
Chemical Trends

AbstractProperties of semiconductors are largely defined by crystal imperfections including native defects. Van der Waals (vdW) semiconductors, a newly emerged class of materials, are no exception: defects exist even in the purest materials and strongly affect their electrical, optical, magnetic, catalytic and sensing properties. However, unlike conventional semiconductors where energy levels of defects are well documented, they are experimentally unknown in even the best studied vdW semiconductors, impeding the understanding and utilization of these materials. Here, we directly evaluate deep levels and their chemical trends in the bandgap of MoS2, WS2 and their alloys by transient spectroscopic study. One of the deep levels is found to follow the conduction band minimum of each host, attributed to the native sulfur vacancy. A switchable, DX center - like deep level has also been identified, whose energy lines up instead on a fixed level across different hosts, explaining a persistent photoconductivity above 400 K.

scholarly journals Lattice Relaxation of the DX Centers in Ga1−x Alx As and of the Pressure–Induced Deep Donors in GaAs

1987 ◽  
Vol 104 ◽  
Author(s):  
M. F. Li ◽  
W. Shan ◽  
P. Y. Yu ◽  
W. L. Ransen ◽  
E. R. Weber ◽  
...  
Keyword(s):  
Deep Level ◽  
Lattice Relaxation ◽  
Transient Techniques ◽  
Large Lattice ◽  
Defect Energies ◽  
Deep Donor ◽  
Diamond Anvil ◽  
Dx Center ◽  
Capacitance Transient ◽  
Experimental Pressure

ABSTRACTDeep Level Transient Spectroscopies (DLTS) and capacitance transient techniques have been applied to GaAs:Si and to Ga1−xAlxAs:Te (x=0.35) under quasi-hydrostatic pressure using a diamond anvil cell. By substituting the experimental pressure coefficients of the defect energies into a model proposed by Li and Yu (Solid State Commun. 61, 13 (1987)) we concluded that both the DX center in the GaAlAs alloy and the pressure-induced deep donor (PIDD) in GaAs have large lattice relaxations associated with them.

Charge Trapping by Deep Donors in Si-Doped AlxGa1-xAS

1985 ◽  
Vol 46 ◽  
Author(s):  
P. M. Mooney ◽  
N. S. Caswell ◽  
P. M. Solomon ◽  
S. L. Wright
Keyword(s):  
Activation Energy ◽  
Energy Range ◽  
Charge Trapping ◽  
Lattice Relaxation ◽  
Persistent Photoconductivity ◽  
Relaxation Model ◽  
Thermally Activated ◽  
Large Lattice ◽  
Si Doped ◽  
Kinetics Of

AbstractThe kinetics of charge capture by deep donors in AlxGa1-xAs have been measured. The time dependence indicates that a single energy cannot be used to describe the trap. A model assuming thermally activated capture into a resonance in the conduction band with a range of energies gives excellent fits to the data and provides a measure of the energy range for the trap. This model is consistent with the large lattice relaxation model for DX centers. The increase of the activation energy for capture as the Al mole fraction is decreased contradicts the model which attributes the decay of the persistent photoconductivity to tunneling through the heterojunction barrier in modulationdoped structures.

DX Center Analysis in Sn DOPED AlGaAs Layer of Double Heterostructures

1987 ◽  
Vol 104 ◽  
Author(s):  
M. Kaniewska ◽  
J. Kaniewski
Keyword(s):  
Thermal Activation ◽  
Lattice Relaxation ◽  
Electron Capture Cross Section ◽  
Final State ◽  
Al Content ◽  
Double Heterostructures ◽  
Algaas Layer ◽  
Large Lattice ◽  
Dx Center ◽  
Dlts Spectra

ABSTRACTCapacitance as well as photovoltage response methods have been used to analyse DX centers in the N–type AlGaAs:Sn layer of double heterostructures. DLTS spectra have revealed two deep traps. The first center (ΔE1 = 0.20eV) has been interpreted as the DX center related to Sn. In this paper, it is suggested that the second trap, with thermal activation energy equal to ΔE2 = 0.33eV, is also a DX center due to Sn, connected with another final state (the L minimum) of thermal processes. C-T characteristics and DLTS spectra have been compared with photovoltage spectra to find a correlation between the trap populations and Al content. The binding energy of the trap 2, as well as the temperature dependence of the electron capture cross-section, have been determined from measurements of the transition region width. Photoionization measurements confirm that there is large lattice relaxation when an electron is captured at the trap.

Pressure-dependent DLTS Experiments on Si-DOPED AlGaAs

1987 ◽  
Vol 104 ◽  
Author(s):  
John W. Farmer ◽  
Harold P. Hjalmarson ◽  
G. A. Samara
Keyword(s):  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Defect Complex ◽  
Persistent Photoconductivity ◽  
Dx Centers ◽  
Si Doped ◽  
Dx Center ◽  
Transient Spectroscopy ◽  
Dlts Spectra

ABSTRACTPressure dependent Deep Level Transient Spectroscopy (DLTS) experiments are used to measure the properties of the deep donors (DX-centers) responsible for the persistent photoconductivity effect in Si-doped AlGaAs. The sample dependence of the DLTS spectra shows evidence for a defect complex involved in the DX-center.

Persistent Photoconductivity in n-Type GaN

1996 ◽  
Vol 449 ◽  
Author(s):  
A. E. Wickenden ◽  
G. Beadie ◽  
D. D. Koleske ◽  
W. S. Rabinovich ◽  
J. A. Freitas
Keyword(s):  
Room Temperature ◽  
Deep Level ◽  
Persistent Photoconductivity ◽  
Acceptor Pair ◽  
Deep Level Defect ◽  
Sapphire Substrates ◽  
Defect Centers ◽  
Donor Acceptor ◽  
Si Doped ◽  
Donor Acceptor Pair

ABSTRACTPersistent photoconductivity has been observed in n-type Si-doped GaN grown on sapphire substrates by metalorganic vapor phase epitaxy. The effect has been seen both in films which are of electrically high quality, based on low temperature photoluminescence (PL) and Hall analysis, and in films which either appear to be compensated or which exhibit strong donor-acceptor pair recombination. The photoconductivity has been observed to persist for several days at room temperature (300K). Modeling of the resistance recovery by a stretched exponential treatment may suggest a distribution of deep level defect centers in the Si-doped GaN films.

Defects in quantum dots of IIB–VI semiconductors

2008 ◽  
Vol 16 (3) ◽  
Author(s):  
V. Babentsov ◽  
F. Sizov
Keyword(s):  
Quantum Dots ◽  
Deep Level ◽  
Great Part ◽  
Emission Spectra ◽  
Structural Defects ◽  
Deep Level Defect ◽  
Native Defects ◽  
Characterization Methods ◽  
Defect Passivation ◽  
Excitonic Emission

AbstractThis review discusses the properties of structural defects in quantum dots of IIB–VI semiconductors. A great part of this knowledge has been developed in the last years and combined with the improvement in passivation technologies has contributed significantly to the nanotechnology.In this review we introduced the main characterization methods which are used for the study of defects in the nanoform of semiconductors, presented a short description of how native defects can influence the emission spectra, underlined the restrictions which the Auger and deep-level defect recombination imposes on the excitonic emission. We also highlighted the importance of the defect passivation associated with efficiency and photostability of devices.

Persistent Photoconductivity And Thermal Recovery Kinetics Of Low Energy Ar + Bombarded GaAs

1991 ◽  
Vol 223 ◽  
Author(s):  
A. Vaseashta ◽  
L. C. Burton
Keyword(s):  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Thermal Recovery ◽  
Low Energy ◽  
Persistent Photoconductivity ◽  
Transport Parameters ◽  
Excellent Correlation ◽  
Proposed Model ◽  
Transient Spectroscopy ◽  
Kinetics Of

ABSTRACTKinetics of persistent photoconductivity, photoquenching, and thermal and optical recovery observed in low energy Ar+ bombarded on (100) GaAs surfaces have been investigated. Rate and transport equations for these processes were derived and simulated employing transport parameters, trap locations and densities determined by deep level transient spectroscopy. Excellent correlation was obtained between the results of preliminary simulation and the experimentally observed values. The exponential decay of persistent photoconductivity response curve was determined to be due to metastable electron traps with longer lifetime and is consistent with an earlier proposed model.

The Peculiarities of Deep Level Defect Passivation in SI by Atomic Hydrogen

1989 ◽  
Vol 6-7 ◽  
pp. 341-342
Author(s):  
Sergei V. Koveshnikov ◽  
S.V. Nosenko ◽  
Eugene B. Yakimov
Keyword(s):  
Atomic Hydrogen ◽  
Deep Level ◽  
Deep Level Defect ◽  
Defect Passivation
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