Electron Irradiation Induced Trap In N-Type Gan

1997 ◽  
Vol 482 ◽  
Author(s):  
Z-Q. Fang ◽  
J. W. Hemsky ◽  
D. C. Look ◽  
M. P. Mack ◽  
R. J. Molnar ◽  
...  
Keyword(s):  
Electron Irradiation ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Chemical Vapor ◽  
Hydride Vapor Phase Epitaxy ◽  
Organic Chemical ◽  
Electric Field Effects ◽  
Metal Organic ◽  
Transient Spectroscopy ◽  
Organic Chemical Vapor Deposition

AbstractA 1-MeV-electron-irradiation (EI) induced trap at Ec-0.18 eV is found in n-type GaN by deep level transient spectroscopy (DLTS) measurements on Schottky barrier diodes, fabricated on both metal-organic-chemical-vapor-deposition and hydride-vapor-phase-epitaxy material grown on sapphire. The 300-K carrier concentrations of the two materials are 2.3 × 1016 cm−3 and 1.3 × 1017 cm−3, respectively. Up to an irradiation dose of 1 × 1015 cm−2, the electron concentrations and pre-existing traps in the GaN layers are not significantly affected, while the EI-induced trap is produced at a rate of at least 0.2 cm−1. The DLTS peaks in the two materials are shifted slightly, possibly due to electric-field effects. Comparison with theory suggests that the defect is most likely associated with the N vacancy or Ga interstitial.

Deep Level Transient Spectroscopy Analysis of an Anatase Epitaxial Film Grown by Metal Organic Chemical Vapor Deposition

2001 ◽  
Vol 40 (Part 2, No. 4B) ◽  
pp. L404-L406 ◽  
Author(s):  
Takahira Miyagi ◽  
Tomoyuki Ogawa ◽  
Masayuki Kamei ◽  
Yoshiki Wada ◽  
Takefumi Mitsuhashi ◽  
...  
Keyword(s):  
Vapor Deposition ◽  
Deep Level Transient Spectroscopy ◽  
Epitaxial Film ◽  
Deep Level ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Spectroscopy Analysis ◽  
Metal Organic ◽  
Transient Spectroscopy ◽  
Organic Chemical Vapor Deposition

Comparison of deep level spectra of MBE- and MOCVD-grown InGaAsN

2002 ◽  
Vol 719 ◽  
Author(s):  
R. J. Kaplar ◽  
S. A. Ringel ◽  
Steven R. Kurtz ◽  
A. A. Allerman ◽  
J. F. Klem
Keyword(s):  
Deep Level ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Mbe Growth ◽  
Growth Technique ◽  
Deep Electron Trap ◽  
Metal Organic ◽  
Similar Materials ◽  
Transient Spectroscopy ◽  
Organic Chemical Vapor Deposition

AbstractDeep level transient spectroscopy (DLTS) studies of both p-type (uid) and n-type (Sidoped), lattice-matched, 1.05 eV bandgap InGaAsN grown by molecular-beam epitaxy (MBE) are reported, and the results are compared to previous measurements of similar materials grown by metal-organic chemical-vapor deposition (MOCVD). In MBE-grown p-type InGaAsN, two majority-carrier hole traps were observed: H3' (0.37 eV) and H4' (0.51 eV), and no evidence was found for the presence of minority-carrier electron traps. These two traps appear to be similar to two levels, H3 (0.48 eV) and H4 (0.5 eV), previously characterized in MOCVD-grown InGaAsN. In MBE-grown n-type InGaAsN, we observed a shallow distribution of electron levels, E1' (0 < EA < 0.35 eV), as well as a deep electron trap E4' (0.56 eV) and a deep hole trap H5' (0.71 eV). E1' appears to be coincident with a superposition of two levels observed in MOCVD-grown InGaAsN, a shallow distribution termed E1 (0 < EA < 0.20 eV) and a discrete (though broadened) level E3 (0.34 eV). Further, E4' appears to be similar in character to a level observed in MOCVD-grown material, E4 (0.82 eV), although a disparity in activation energy exists. This disparity may be due to a temperature-dependent capture cross-section for one or both levels, a possibility that is currently under investigation. In contrast, H5' appears to have no analogue in MOCVD-grown material and thus may be unique to the MBE growth technique.

Photoluminescence study of deep-level defects in undoped GaN

2001 ◽  
Vol 693 ◽  
Author(s):  
M. A. Reshchikov ◽  
H. Morkoç ◽  
S. S. Park ◽  
K. Y. Lee
Keyword(s):  
Deep Level ◽  
Broad Band ◽  
Chemical Vapor ◽  
Hydride Vapor Phase Epitaxy ◽  
Organic Chemical ◽  
Metal Organic ◽  
Identical Position ◽  
Lift Off ◽  
The One ◽  
Organic Chemical Vapor Deposition

AbstractWe studied photoluminescence (PL) and PL excitation (PLE) spectra in a large number of undoped GaN layers grown on sapphire by molecular beam epitaxy (MBE), metal-organic chemical vapor deposition (MOCVD) and hydride vapor phase epitaxy (HVPE). The HVPE-grown GaN layers with thickness of ~200 m m were separated from the sapphire substrate by laser lift-off and represented bulk freestanding templates of very high quality. Identical position and shape of the YL band were reproduced in many samples grown by MBE and MOCVD: maximum at ~2.23 eV and full width at half maximum (FWHM) of about 460 meV at room temperature. However, in some samples the band maximum was observed at about 2.0 eV. The freestanding templates reveal a broad band (FWHM=530-680 meV) whose position depends on excitation energy and intensity, varying from 2.22 eV to 2.47 eV. PLE spectra taken from various samples represented a broad band with apparent maximum at about 3.3 eV. For below-gap excitation, the intensity of the YL band was independent of temperature except for the one in the freestanding template. The latter was temperature independent above 60 K, however at lower temperatures the PL intensity decreased by 5 times. An activation energy of 15 meV has been determined that is related to a barrier in the adiabatic potential in the excited state of the defect.

scholarly journals Evidence of the Meyer-Neldel Rule in InGaAsN Alloys: Consequences for Photovoltaic Materials

2003 ◽  
Vol 763 ◽  
Author(s):  
Steven W. Johnston ◽  
Richard S. Crandall
Keyword(s):  
Deep Level ◽  
Chemical Vapor ◽  
Rf Plasma ◽  
Organic Chemical ◽  
Isokinetic Temperature ◽  
Deep Hole ◽  
Growth Technique ◽  
Metal Organic ◽  
Transient Spectroscopy ◽  
Organic Chemical Vapor Deposition

AbstractWe present data showing the potential adverse effects on photovoltaic device performance of all traps in InGaAsN. Deep-level transient spectroscopy measurements were performed on InGaAsN samples grown by both metal-organic chemical vapor deposition and RF plasma-assisted molecular-beam epitaxy. For each growth technique, we studied samples with varying nitrogen composition ranging from 0% to 2.2%. A deep hole trap with activation energy ranging between 0.5 and 0.8 eV is observed in all samples. These data clearly obey the Meyer-Neldel rule, which states that all traps have the same emission rate at the isokinetic temperature. A fit of our trap data gives an isokinetic temperature of 350 K. We find that the emission time for all deep hole traps is on the order of milliseconds at room temperature. This means that both deep and shallow traps emit slowly at the operating temperature of solar cells—thus, the traps can be recombination centers.

Deep Level Centers in Carbon-Doped High Resistivity GaN

2014 ◽  
Vol 997 ◽  
pp. 492-495
Author(s):  
Huan Cui ◽  
Li Wu Lu ◽  
Ling Sang ◽  
Bai He Chen ◽  
Zhi Wei He ◽  
...  
Keyword(s):  
Deep Level ◽  
Chemical Vapor ◽  
Deep Levels ◽  
Hall Measurement ◽  
High Resistivity ◽  
Organic Chemical ◽  
Carbon Doped ◽  
Metal Organic ◽  
High Level ◽  
Organic Chemical Vapor Deposition

The deep levels of carbon doped high resistivity (HR) GaN samples grown by metal-organic chemical vapor deposition (MOCVD) has been investigated using thermally stimulated current (TSC) spectroscopy and high temperature (HT) Hall measurement. Two different thickness of 100 and 300 nm were used to be compared. It was found that four distinct deep levels by TSC and one deep level by HT Hall measurement were observed in both samples, which means great help for the decrease of leakage current and lifetime limitations of device utilizing the structure. The activation energy of these levels was calculated and their possible origins were also proposed. The low temperature traps, might be related to VN, 0.50 and 0.52eV related to incorporate a high level carbon, 0.57eV related to VGa, 0.59eV related to CGaor NGa, 0.91 and 0.97eV related to interstitial N1.

Characteristics of Alpha-Radiation-Induced Deep Level Defects in p-Type InP Grown by Metal-Organic Chemical Vapor Deposition

1998 ◽  
Vol 37 (Part 1, No. 8) ◽  
pp. 4595-4602 ◽  
Author(s):  
Aurangzeb Khan ◽  
Mohd Zafar Iqbal ◽  
Umar Saeed Qurashi ◽  
Masafumi Yamaguchi ◽  
Nasim Zafar ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Deep Level ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Alpha Radiation ◽  
Metal Organic ◽  
Radiation Induced ◽  
P Type ◽  
Organic Chemical Vapor Deposition

As-grown deep-level defects in n-GaN grown by metal–organic chemical vapor deposition on freestanding GaN

2012 ◽  
Vol 112 (5) ◽  
pp. 053513 ◽  
Author(s):  
Shang Chen ◽  
Unhi Honda ◽  
Tatsunari Shibata ◽  
Toshiya Matsumura ◽  
Yutaka Tokuda ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Deep Level ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

Deep Centers and Their Capture Barriers in MOCVD-Grown GaN

2001 ◽  
Vol 692 ◽  
Author(s):  
Daniel K. Johnstonea ◽  
Mohamed Ahoujjab ◽  
Yung Kee Yeoc ◽  
Robert L. Hengeholdc ◽  
Louis Guidod
Keyword(s):  
Deep Level ◽  
Chemical Vapor ◽  
Energy Concentration ◽  
Organic Chemical ◽  
High Concentration ◽  
Current Voltage ◽  
Carrier Traps ◽  
Metal Organic ◽  
Transient Spectroscopy ◽  
Capacitance Transient

AbstractGaN and its related alloys are being widely developed for blue-ultraviolet emitting and detection devices as well as high temperature, high power, and high frequency electronics. Despite the fast improvement in the growth of good quality GaN, a high concentration of deep level defects of yet unconfirmed origins are still found in GaN. For both optical and electronic devices, these deep carrier traps and/or recombination centers are very important and must therefore be understood. In the present work, deep level defects in GaN grown on sapphire substrates by metal organic chemical vapor deposition (MOCVD) have been investigated using Isothermal Capacitance Transient Spectroscopy (ICTS) and Current Voltage Temperature (IVT) measurements. Several deep level electron traps were characterized, obtaining the emission energy, concentration, and capture cross section from a fit of exponentials to the capacitance transients. ICTS was also used to reveal information about the capture kinetics involved in the traps found in GaN by measuring the amplitude of the capacitance transient at each temperature. At a reduced filling pulse where the traps were not saturated, several of them showed marked reduction in capacitance transient amplitude when compared to the transient amplitude measured under conditions where the filling pulse saturates the traps. This reduction in transient amplitude indicates that there is a barrier to carrier capture, in addition to the emission barrier. It has been found that several traps had capture barriers that were significant fractions of the emission energies up to 0.32 eV. These capture barriers may lead to persistent photoconductivity and reduced trapping. In this paper, deep level emission energies as well as capture barrier energies found in MOCVD-grown GAN will be discussed.

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