Determination of donor and acceptor level energies by admittance spectroscopy in 6H SiC

1995 ◽  
Vol 29 (1-3) ◽  
pp. 122-125 ◽  
Author(s):  
C. Raynaud ◽  
C. Richier ◽  
P.N. Brounkov ◽  
F. Ducroquet ◽  
G. Guillot ◽  
...  
Keyword(s):  
Admittance Spectroscopy ◽  
Acceptor Level ◽  
Donor And Acceptor

Stoichiometric Determination of Graphite Intercalation Compounds Using Rutherford Backscatiering Spectrometry

1983 ◽  
Vol 27 ◽  
Author(s):  
L. Salamanca-Riba ◽  
B.S. Elman ◽  
M.S. Dresselhaus ◽  
T. Venkatesan
Keyword(s):  
Experimental Error ◽  
Rutherford Backscattering Spectrometry ◽  
Rutherford Backscattering ◽  
Intercalation Compounds ◽  
Graphite Intercalation Compounds ◽  
X Ray ◽  
Donor And Acceptor ◽  
Graphite Intercalation ◽  
Non Destructive

ABSTRACTRutherford backscattering spectrometry (RBS) is used to characterize the stoichiometry of graphite intercalation compounds (GIC). Specific application is made to several stages of different donor and acceptor compounds and to commensurate and incommensurate intercalants. A deviation from the theoretical stoichiometry is measured for most of the compounds using this non-destructive method. Within experimental error, the RBS results agree with those obtained from analysis of the (00ℓ) x-ray diffractograms and weight uptake measurements on the same samples.

scholarly journals Modulated Photocurrent Spectroscopy for Determination of Electron and Hole Mobilities in Working Organic Solar Cells

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Hiroki Nojima ◽  
Takashi Kobayashi ◽  
Takashi Nagase ◽  
Hiroyoshi Naito
Keyword(s):  
Solar Cells ◽  
Organic Solar Cells ◽  
Power Conversion ◽  
Physical Constant ◽  
Mixing Ratio ◽  
Photocurrent Spectroscopy ◽  
Donor And Acceptor ◽  
Device Structures ◽  
Electron Donor And Acceptor

AbstractCarrier drift mobility is an important physical constant in the charge transport process of organic solar cells (OSCs). Although time-of-flight and space-charge-limited current techniques have been frequently utilized for mobility measurements, the validity of a new method using modulation photocurrent spectroscopy is discussed in this contribution. The advantages of this method are its applicability to working OSCs with optimized device structures and the simultaneous determination of the electron and hole mobilities. These features make it possible to study the relation between the mobility balance and the solar cell characteristics, such as the power conversion efficiency, using only a single working OSC; hence, it is not necessary to fabricate electron-only and hole-only devices for mobility measurements. After carrying out numerical simulations to examine the validity of this method for mobility determination, the dependence of the mobility balance on the mixing ratio of the electron-donor and –acceptor materials is presented.

Aniline Exchange of 2-Aryl-4,5-diphenyl-substituted Isothiazolium Salts

2008 ◽  
Vol 63 (4) ◽  
pp. 473-477 ◽  
Author(s):  
Janine Wolf ◽  
Joachim Sieler ◽  
Bärbel Schulze
Keyword(s):  
Crystal Structure ◽  
Structure Determination ◽  
Crystal Structure Determination ◽  
Aryl Ring ◽  
Isothiazolium Salts ◽  
Donor And Acceptor

Abstract4,5-Diphenyl-substituted N-(R1-aryl)-isothiazolium salts 4 react with anilines 2 (R2) to form 4,5- disubstituted N-(R2-aryl)-isothiazolium salts 4. The influence of donor and acceptor substituents in the N-aryl ring of 4 and in the anilines 2 on the course of the exchange was studied. The structure of the salts 4 was confirmed by a crystal structure determination of 4i.

Electrical and optical investigation of the position of vanadium related defects in the 4H and 6H SiC bandgaps

1996 ◽  
Vol 423 ◽  
Author(s):  
J. R. Jenny ◽  
M. Skowronski ◽  
W. C. Mitchel ◽  
S. R. Smith ◽  
A. O. Evwaraye ◽  
...  
Keyword(s):  
Optical Absorption ◽  
Hall Effect ◽  
Deep Level ◽  
Polarized Light ◽  
Conduction Band Edge ◽  
Optical Investigation ◽  
Admittance Spectroscopy ◽  
Acceptor Level ◽  
Transient Spectroscopy ◽  
Spectroscopy Optical

AbstractHall effect, deep level transient spectroscopy, optical absorption, and optical admittance spectroscopy were employed to determine the position of the vanadium acceptor and vanadiumnitrogen complex in vanadium- and nitrogen-doped 4H and 6H SiC. Hall effect results indicate that the acceptor position in 4H(6H) SiC is 0.80(0.66) eV beneath the conduction band edge. The DLTS signature of the defect in the 4H polytype showed an ionization energy of 806 meV and a capture cross section of 1.8×10−16 cmr−2 The optical absorption measurements proved that the acceptor level investigated is related to isolated vanadium, and therefore the vanadium acceptor level. Based upon DLTS and SIMS measurements, the maximum solubility of vanadium in SiC was determined to the 3×10−17 crn3. An examination of polarized light experiments indicates that vanadium also complexes with another element to form electronic(at 5000 cm−1) and vibrational absorption(at 683 cm−1) bands. While the other constituent cannot be identified, evidence suggests that nitrogen is a likely candidate. This complex introduces a deep level at Ec−0.78 eV as determined using optical admittance spectroscopy.

Determination of donor and acceptor densities in high‐purity GaAs from photoluminescence analysis

1990 ◽  
Vol 56 (2) ◽  
pp. 177-179 ◽  
Author(s):  
Z. H. Lu ◽  
M. C. Hanna ◽  
D. M. Szmyd ◽  
E. G. Oh ◽  
A. Majerfeld
Keyword(s):  
High Purity ◽  
Donor And Acceptor

The gold donor and acceptor level in p-type silicon

1984 ◽  
Vol 50 (12) ◽  
pp. 1051-1055 ◽  
Author(s):  
P. van Staa ◽  
R. Kassing
Keyword(s):  
Acceptor Level ◽  
Type Silicon ◽  
Donor And Acceptor ◽  
P Type

Metastable VO2 Complexes in Silicon: Experimental and Theoretical Modeling Studies

2005 ◽  
Vol 108-109 ◽  
pp. 223-228 ◽  
Author(s):  
L.I. Murin ◽  
J. Lennart Lindström ◽  
Vladimir P. Markevich ◽  
I.F. Medvedeva ◽  
Vitor J.B. Torres ◽  
...  
Keyword(s):  
Density Functional ◽  
Theoretical Study ◽  
Interstitial Oxygen ◽  
Vibrational Modes ◽  
Acceptor Level ◽  
Acceptor State ◽  
Metastable Form ◽  
Local Vibrational Modes ◽  
Co Doped

We report on a combined experimental and theoretical study of the metastable form of the vacancy-dioxygen defect in Si labeled VO∗ 2. Important new experimental observations are the detection of mixed local vibrational modes of VO∗ 2 in 16O,18O co-doped samples, the determination of the position of LVM bands for the negatively charged defect, and an assignment of an acceptor level at about Ec − 0.05 eV. Defect energetics, electrical levels and LVM frequencies of the VO∗ 2 complex are also investigated by ab-initio density-functional modeling.We find it to be a bistable defect which accounts well for the experimental data. The metastable form produces an acceptor state at 0.05 eV below Ec, and can be thought of as a VO defect perturbed by interstitial oxygen.

Determination of the GaN/AlN band offset via the (‐/0) acceptor level of iron

1994 ◽  
Vol 65 (17) ◽  
pp. 2211-2213 ◽  
Author(s):  
J. Baur ◽  
K. Maier ◽  
M. Kunzer ◽  
U. Kaufmann ◽  
J. Schneider
Keyword(s):  
Band Offset ◽  
Acceptor Level

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

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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