Investigation of relation between Ga concentration and defect levels of Al/Cu(In,Ga)Se2 Schottky junctions using admittance spectroscopy

AbstractAdmittance spectroscopy measurement has been performed on NiOx thin films with various oxygen compositions (x=1.0-1.2) in order to characterize localized defect levels. The activation energy and concentration of localized defect levels in NiOx films with low oxygen composition (x≤1.07) are 120-170 meV and lower than 2×1019 cm-3, respectively. From I-V measurement of the Pt/NiOx/Pt structures, samples with high oxygen composition (x≥1.10) did not show resistance switching operation, while samples with low oxygen composition (x≤1.07) did. The best oxygen composition of NiOx thin films turned out to be 1.07 in order to realize repeatable and stable resistance switching operation.

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Characterization of Defects in N-Type 6H-SiC Single Crystals by Optical Admittance Spectroscopy

MRS Proceedings ◽

10.1557/proc-339-711 ◽

1994 ◽

Vol 339 ◽

Cited By ~ 1

Author(s):

A. O. Evwaraye ◽

S. R. Smith ◽

W. C. Mitchel

Keyword(s):

Transition Metal ◽

Single Crystals ◽

Admittance Spectroscopy ◽

Donor Atom ◽

Deep Defect ◽

Metal Impurities ◽

Transition Metal Impurities ◽

Defect Levels ◽

Type Conduction

ABSTRACTOptical admittance spectroscopy is a technique for measuring the conductance and capacitance of a junction under illumination as a function of the wavelength of the light and the frequency of the measuring AC signal. This technique has been applied to characterize deep defect levels in 6H-SiC:N. Nitrogen is a donor atom in 6H-SiC which substitutes for carbon in three inequivalent sites (h, k1, k2). giving rise to n-type conduction. Deep defect levels attributable to transition metal impurities have also been identified in 6H-SiC:N. We have examined persistent photoconductance in this material by optical admittance spectroscopy.

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Admittance spectroscopy analysis on the interfacial defect levels in the surface-activated bonding of GaAs

2016 IEEE 43rd Photovoltaic Specialists Conference (PVSC) ◽

10.1109/pvsc.2016.7750051 ◽

2016 ◽

Author(s):

Daiji Yamashita ◽

Kentaroh Watanabe ◽

Masahisa Fujino ◽

Takuya Hoshii ◽

Yoshitaka Okada ◽

...

Keyword(s):

Admittance Spectroscopy ◽

Spectroscopy Analysis ◽

Interfacial Defect ◽

Defect Levels

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The Optical Admittance Spectroscopy of the Vanadium Donor and Acceptor Levels in Semi-Insulating 4H-SiC and 6H-SiC

Materials Science Forum ◽

10.4028/www.scientific.net/msf.527-529.647 ◽

2006 ◽

Vol 527-529 ◽

pp. 647-650

Author(s):

Won Woo Lee ◽

Mary Ellen Zvanut

Keyword(s):

Thermal Relaxation ◽

Admittance Spectroscopy ◽

Defect Level ◽

Defect Complexes ◽

Donor And Acceptor ◽

Defect Levels

The purpose of this study is to determine the vanadium defect levels in semi-insulating 4H-SiC and 6H-SiC using optical admittance spectroscopy (OAS). OAS data show several distinct peaks for the vanadium-doped SI 4H-SiC and 6H-SiC. Comparison of the data for the two polytypes suggests that peaks at 0.67 ± 0.02 eV and 0.70 ± 0.02 eV in 6H substrates and 0.75 ± 0.02 eV in 4H substrates are related to V3+/4+ levels at the cubic sites. A peak at 0.87 ± 0.02 eV in the 6H sample is assigned to the same defect level at the hexagonal site and the associated transition in 4H was observed at 0.94 ± 0.02 eV in our spectra. The donor levels are thought to be related to peaks at 1.94 ± 0.05 eV and 1.87 ± 0.05 eV in 4H and 6H samples, respectively. The differences between the values obtained from the optical admittance measurements and those reported in the literature are attributed to thermal relaxation and/or contributions from defect complexes.

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Investigation of Defect Levels in Mg-Doped GaN Schottky Structures by Thermal Admittance Spectroscopy

physica status solidi (b) ◽

10.1002/1521-3951(200111)228:2<385::aid-pssb385>3.0.co;2-6 ◽

2001 ◽

Vol 228 (2) ◽

pp. 385-389

Author(s):

N.D. Nguyen ◽

M. Germain ◽

M. Schmeits ◽

B. Schineller ◽

M. Heuken

Keyword(s):

Admittance Spectroscopy ◽

Defect Levels ◽

Mg Doped

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Characterization of Defects in N-Type 6H-SiC Single Crystals by Optical Admittance Spectroscopy

MRS Proceedings ◽

10.1557/proc-325-353 ◽

1993 ◽

Vol 325 ◽

Cited By ~ 3

Author(s):

A.O. Evwaraye ◽

S.R. Smith ◽

W.C. Mitchel

Keyword(s):

Single Crystals ◽

Admittance Spectroscopy ◽

Donor Atom ◽

Deep Defect ◽

Metal Impurities ◽

Transition Metal Impurities ◽

Defect Levels ◽

First Time ◽

Type Conduction

AbstractOptical admittance spectroscopy is a technique for measuring the conductance and capacitance of a junction under illumination as a function of the wavelength of the light and the frequency of the measuring AC signal. For the first time, this technique is applied to characterize deep defect levels in 6H-SiC:N. Nitrogen is a donor atom in 6H-SiC which substitutes for carbon in three inequivalent sites (h, kl, k2). giving rise to n-type conduction. Deep defect levels attributible to transition metal impurities have been identified in 6H-SiC:N by optical admittance spectroscopy.

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Effect of C/B Sequential Implantation on the B Acceptors in 4H-SiC

MRS Proceedings ◽

10.1557/proc-640-h5.32 ◽

2000 ◽

Vol 640 ◽

Author(s):

Yoshitaka Nakano ◽

Tetsu Kachi ◽

Hiroshi Tadano ◽

Rajesh Kumar Malhan

Keyword(s):

Ionization Energy ◽

Hole Concentration ◽

Deep Levels ◽

Admittance Spectroscopy ◽

Deep Defect ◽

Complex Defect ◽

Rich Condition ◽

Defect Levels ◽

Expected Increase

ABSTRACTWe have systematically investigated the effect of C/B sequential implantation on the B-related acceptors and deep levels in 4H-SiC using thermal admittance spectroscopy. With increasing concentration of co-implanted C, the density of deep levels was found to start decreasing and to be completely suppressed for the C and B ratio of 1:1. Moreover, the density and ionization energy of B acceptors were seen to start increasing and lowering, respectively, with increasing C concentration. However, we found that excess C-content leads to the formation of a new complex defect. The C-V results also support the expected increase in the total hole concentration with increasing concentration of the co-implanted C-atoms, which is followed by a decrease in the concentration under C-rich condition. This is in reasonable agreements with the behavior of the B acceptors and deep defect levels. Therefore, the concentration of co-implanted C-atoms is considered to be very sensitive to the formation of the B acceptor levels.

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