Hydrogen Local Vibrational Modes in Compound Semiconductors

1998 ◽  
Vol 513 ◽  
Author(s):  
M. D. Mccluskey
Keyword(s):  
Hydrostatic Pressure ◽  
Resonant Interaction ◽  
Host Lattice ◽  
Local Mode ◽  
Vibrational Modes ◽  
Temperature Dependent ◽  
Local Vibrational Mode ◽  
Combination Modes ◽  
Stretch Mode ◽  
Anharmonic Coupling

ABSTRACTLocal vibrational mode (LVM) spectroscopy of hydrogen and deuterium in GaP, AlSb, ZnSe, and GaN has provided important information about the structures of dopanthydrogen complexes and their interaction with the host lattice. In GaN:Mg, for example, hydrogen binds to a host nitrogen which is adjacent to the magnesium acceptor. In GaP and ZnSe, it has been demonstrated that the temperature dependent shifts of LVM's are proportional to the lattice thermal energy, a consequence of the anharmonic coupling of the local mode to acoustical phonons.Large hydrostatic pressures have been applied to semiconductors to probe the vibrational properties of hydrogen-related complexes. In GaAs, the pressure dependent shifts of the 12C-H and 13C-H stretch modes have positive curvatures, while the shift of the S-H stretch mode has a negative curvature. This may be related to the fact that in the bond-centered C-H complex, the hydrogen is compressed between the carbon acceptor and one gallium host atom, whereas in the S-H complex, the hydrogen occupies an interstitial position and is not crowded by neighboring atoms. If these trends are general, then hydrostatic pressure may be a powerful tool in determining the position of the hydrogen atom(s) in a complex.In AISb. pressure was utilized to resolve a mystery as to why the Se-D complex gives rise to one stretch mode peak while the Se-H stretch mode splits into three peaks. This anomalous splitting is explained in terms of a new resonant interaction between the stretch mode and combination modes involving a wag mode harmonic and extended lattice phonons. The interaction gives rise to vibrational modes with both localized and extended components. When the temperature or hydrostatic pressure is varied, the modes exhibit anti-crossing behavior.

Infrared Optical Studies of Semiconductors at Large Hydrostatic Pressures

1997 ◽  
Vol 499 ◽  
Author(s):  
E. E. Haller ◽  
M. D. McCluskey
Keyword(s):  
Hydrostatic Pressure ◽  
Vibrational Mode ◽  
Far Infrared ◽  
Infrared Region ◽  
Host Lattice ◽  
Uniaxial Pressure ◽  
Electromagnetic Spectrum ◽  
Local Vibrational Mode ◽  
Specific Complex ◽  
Pressure Medium

ABSTRACTAmong the various external disturbances used in the study of semiconductors, including electric and magnetic fields as well as uniaxial pressure, large hydrostatic pressures can be employed to induce dramatic changes in host lattice, dopant and defect properties. Diamond anvil cells with an appropriate pressure medium (e.g. liquid N2 or alcohol mixtures) allow the application of pressures up to hundreds of kbar. In this pressure range the global conduction band minimum of a semiconductor can become a local minimum. GaAs for example changes near 45 kbar from a direct (Γ-band) to an indirect (X-band) semiconductor. Donors in GaAs and InP transform from their shallow, hydrogenic state to the DX configuration at hydrostatic pressures near 23 and 82 kbar, respectively. This donor configuration change has been studied using local vibrational mode (LVM) spectroscopy in the far infrared region of the electromagnetic spectrum. Recently we have investigated several LVM's of H-containing complexes in GaAs as a function of hydrostatic pressure at liquid He temperatures. Depending on the specific complex we find the LVM frequencies to vary either linearly, sub- or superlinearly with hydrostatic pressure. In the case of O in Si the vibrational mode changes its character from that of a harmonic oscillator to a rotor as pressure is applied. The implications of the pressure dependences of LVM's are discussed.

Temperature Dependent Raman Scattering in CsTiOAsO4 Single Crystal

1995 ◽  
Vol 398 ◽  
Author(s):  
A.R. Guo ◽  
C.-S. Tu ◽  
Ruiwu Tao ◽  
R.S. Katiyar ◽  
Ruyan Guo ◽  
...  
Keyword(s):  
Soft Mode ◽  
Low Frequency ◽  
High Mobility ◽  
Vibrational Modes ◽  
Frequency Range ◽  
Temperature Dependent ◽  
Higher Symmetry ◽  
Phonon Spectra ◽  
Symmetry Structure ◽  
Increasing Temperature

ABSTRACTThe longitudinal (LO) and transverse (TO) A1 vibrational modes have been measured between 30-1200 cm−1 as a function of temperature (30–1240 K) for CsTiOAsO4 (CTA). The frequencies for all corresponding Raman components shifted to lower frequencies on increasing the temperature, however, there is no typical soft-mode like behavior observed in the measured frequency range. The relative intensities of the low frequency bands increase dramatically with increasing temperature due to high mobility of Cs+ ion. A higher symmetry structure taking place above 940K has been confirmed by changes in the phonon spectra.

Temperature-Dependent Vibrational Modes in Sodium Nitrite

1968 ◽  
Vol 174 (3) ◽  
pp. 946-952 ◽  
Author(s):  
M. K. Barnoski ◽  
J. M. Ballantyne
Keyword(s):  
Sodium Nitrite ◽  
Vibrational Modes ◽  
Temperature Dependent

Vibrational Spectroscopic Analysis of Ferroelectric Liquid Crystal MBOPDOB

1998 ◽  
Vol 52 (6) ◽  
pp. 847-850 ◽  
Author(s):  
Lei He ◽  
Zhen Yin ◽  
Ming-Sheng Zhang ◽  
Ze-Xiang Shen ◽  
Hui-Fen Chen
Keyword(s):  
Liquid Crystal ◽  
Room Temperature ◽  
Spectroscopic Analysis ◽  
Ester Group ◽  
Phase Transition Point ◽  
Vibrational Modes ◽  
Ferroelectric Liquid Crystal ◽  
Temperature Dependent ◽  
Vibrational Characteristics ◽  
Shape Changes

Raman spectra of ferroelectric liquid crystal (FLC) D-4-(2-methylbutoxy) phenyl 4-decyloxybenzoate (MBOPDOB) are recorded. All the vibrational modes are assigned, and their vibrational characteristics are studied. It is found that the s-cis and the s-trans conformers of the ester group coexist in the crystal phase at room temperature. By temperature-dependent measurements, the line shape changes due to the transition of the ester group conformation near the crystal-Sm C phase transition point are examined.

scholarly journals Temperature-Dependent Raman Spectroscopic Study of the Double Molybdate KBi(MoO4)2

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5453
Author(s):  
Min Wang ◽  
Changhao Wang ◽  
Jian Wang ◽  
Liming Lu ◽  
Xiaoye Gong ◽  
...  
Keyword(s):  
High Temperature ◽  
Raman Spectra ◽  
Monoclinic Phase ◽  
Raman Band ◽  
Vibrational Modes ◽  
Temperature Dependent ◽  
Raman Spectroscopic ◽  
Thermal Stability Of ◽  
Good Agreement

In situ high-temperature Raman spectra of polycrystalline KBi(MoO4)2 were recorded from room temperature to 1073 K. Thermal stability of the monoclinic KBi(MoO4)2 was examined by temperature-dependent XRD. The monoclinic phase transformed into the scheelite tetragonal structure at 833 K, and then to the monoclinic phase at 773 K. Quantum chemistry ab initio calculation was performed to simulate the Raman spectra of the structure of KBi(MoO4)2 high-temperature melt. The experimental Raman band at 1023 K was deconvoluted into seven Gaussian peaks, and the calculated results were in good agreement with the experimental data. Therefore, the vibrational modes of Raman peaks of molten KBi(MoO4)2 were assigned. It was confirmed that the isolated structure of [Bi(MoO4)2]− monomer, consisting of Mo6+ centers and Bi3+ sub-centers connected by edge-sharing, mainly exists in the melt of KBi(MoO4)2.

Phase Changes in Fe(III)OCl–RNH2-Intercalation Complexes

1984 ◽  
Vol 39 (9) ◽  
pp. 1193-1198 ◽  
Author(s):  
Armin Weiss ◽  
Jin Ho Choy
Keyword(s):  
Room Temperature ◽  
Host Lattice ◽  
Phase Changes ◽  
Temperature Dependent ◽  
Chain Molecules ◽  
Intercalation Complexes ◽  
Long Chain

Iron(III)oxide chloride is capable of intercalating ammonia and amines into its layer lattice. Long chain molecules form bilayers with extended chains almost perpendicular to the host lattice layers at room temperature (intercalate composition): FeOCl · (0.54 ±0.03)n -CxH2x+1NH2 with x ≥ 12) and tilted by 57° at about 100-110 °C (intercalate composition: FeOCl · (0.45 ±0.02)n-CxH2x+1NH2 with ≥12). The temperature-dependent changes in basal spacings between 20 and 110 °C are complex. Above 120 °C the layers of the host lattice are altered irreversibly by substitution and HCl-release to FeOCl1-y(-NHCxH2x+1)y with y ≤ ca. 0.4.

Femtosecond Spectroscopy of Ferroelectric Perovskites: Explanation of Anomalous Polariton Dynamics in Lithium Tantalate

1992 ◽  
Vol 293 ◽  
Author(s):  
Gary P. Wiederrecht ◽  
T. P. Dougherty ◽  
L. Dhar ◽  
K. A. Nelson
Keyword(s):  
Pulse Shaping ◽  
Stimulated Raman Scattering ◽  
Single Pulse ◽  
Lithium Tantalate ◽  
Pulse Excitation ◽  
Vibrational Modes ◽  
Temperature Dependent ◽  
Time Resolved ◽  
Optical Pulse Shaping ◽  
Impulsive Stimulated Raman Scattering

AbstractTime resolved impulsive stimulated Raman scattering (ISRS) is used to characterize the lowest frequency A1 phonon-polariton mode in lithium tantalate. The anomalously high and wavevector-dependent damping rates observed are explained in terms of coupling of the polariton to a weakly Raman-active relaxational mode and to two heavily damped vibrational modes. The dynamics of the relaxational mode are explored further through temperature dependent ISRS studies. Femtosecond optical pulse shaping is used for multiple pulse ISRS at temperatures lower than 120K where single pulse excitation led to photorefractive damage.

scholarly journals The Trivacancy and Trivacancy-Oxygen Family of Defects in Silicon

2013 ◽  
Vol 205-206 ◽  
pp. 181-190 ◽  
Author(s):  
Vladimir P. Markevich ◽  
Anthony R. Peaker ◽  
Bruce Hamilton ◽  
S.B. Lastovskii ◽  
Leonid I. Murin ◽  
...  
Keyword(s):  
Deep Level Transient Spectroscopy ◽  
Minority Carrier ◽  
Vibrational Mode ◽  
Deep Level ◽  
Vibrational Modes ◽  
Carrier Injection ◽  
Local Vibrational Mode ◽  
Diffusion Paths ◽  
Transient Spectroscopy ◽  
And Diffusion

The data obtained recently from combined deep-level-transient spectroscopy (DLTS), local vibrational mode (LVM) spectroscopy and ab-initio modeling studies on structure, electronic properties, local vibrational modes, reconfiguration and diffusion paths and barriers for trivacancy (V3) and trivacancy-oxygen (V3O) defects in silicon are summarized. New experimental results on the introduction rates of the divacancy (V2) and trivacancy upon 4 MeV electron irradiation and on the transformation of V3 from the fourfold coordinated configuration to the (110) planar one upon minority carrier injection are reported. Possible mechanisms of the transformation are considered and discussed.

scholarly journals Ultrafast Vibrational Dynamics of CO Ligands on RuTPP/Cu(110) under Photodesorption Conditions

Surfaces ◽  
2019 ◽  
Vol 2 (1) ◽  
pp. 117-130 ◽  
Author(s):  
Takuma Omiya ◽  
Yousoo Kim ◽  
Rasmita Raval ◽  
Heike Arnolds
Keyword(s):  
Low Frequency ◽  
Blue Shift ◽  
Vibrational Modes ◽  
Vibrational Dynamics ◽  
Sum Frequency ◽  
Stretching Vibration ◽  
A Charge ◽  
Anharmonic Coupling ◽  
Vibration Coupling ◽  
Probe Spectroscopy

We have studied CO coordinated to ruthenium tetraphenylporphyrin (RuTPP)/Cu(110) and directly adsorbed to Cu(110), using femtosecond pump-sum frequency probe spectroscopy, to alter the degree of electron-vibration coupling between the metal substrate and CO. We observe the facile femtosecond laser-induced desorption of CO from RuTPP/Cu(110), but not from Cu(110). A change in the vibrational transients, in the first few picoseconds, from a red- to blue-shift of the C–O stretching vibration under photodesorption conditions, was also observed. This drastic change can be explained, if the cause of the C–O frequency redshift of Cu(110) is not the usually-assumed anharmonic coupling to low frequency vibrational modes, but a charge transfer from hot electrons to the CO 2π* state. This antibonding state shifts to higher energies on RuTPP, removing the C–O redshift and, instead, reveals a blueshift, predicted to arise from electron-mediated coupling between the coherently excited internal stretch and low frequency modes in the system.

Sign in / Sign up

Export Citation Format

Share Document