Electronic excitations and longitudinal optical phonon modes of self-assembled CdSe quantum dots revealed by microprobe studies

1999 ◽  
Vol 74 (17) ◽  
pp. 2489-2491 ◽  
Author(s):  
M. Lowisch ◽  
M. Rabe ◽  
F. Kreller ◽  
F. Henneberger
Keyword(s):  
Quantum Dots ◽  
Optical Phonon ◽  
Longitudinal Optical ◽  
Longitudinal Optical Phonon ◽  
Cdse Quantum Dots ◽  
Electronic Excitations ◽  
Phonon Modes ◽  
Self Assembled

Interface and longitudinal optical phonon modes in cylindrical quantum dots

1999 ◽  
Vol 59 (3) ◽  
pp. 1621-1624 ◽  
Author(s):  
Clément Kanyinda-Malu ◽  
Rosa María de la Cruz
Keyword(s):  
Quantum Dots ◽  
Optical Phonon ◽  
Longitudinal Optical ◽  
Longitudinal Optical Phonon ◽  
Phonon Modes

Electron-Phonon Scattering in GaN/AlN and GaAs/AlAs Quantum Wells

1997 ◽  
Vol 482 ◽  
Author(s):  
T. F. Forbang ◽  
C. R. McIntyre
Keyword(s):  
Quantum Wells ◽  
Optical Phonon ◽  
Phonon Spectrum ◽  
Phonon Scattering ◽  
Relaxation Times ◽  
Longitudinal Optical ◽  
Longitudinal Optical Phonon ◽  
Phonon Modes ◽  
Optical Phonon Scattering ◽  
Electron Phonon Scattering

AbstractWe have studied the effects on the phonon spectrum and on the electron-longitudinal optical phonon scattering in GaN/AlN and GaAs/AlAs quantum wells. Phonon modes and potentials have been calculated for both systems. Results for emission due to electroninterface phonons interactions are presented. We will discuss the implications for relaxation times and electron mobility due to modified LO-phonon scattering in both systems.

Nondestructive Characterizations of Au-Catalyzed GaAs Nanowires on GaAs(111)B Substrates via Identifications of 1st Order Optical Phonon Modes Using μ-Raman Spectroscopy

2020 ◽  
Vol 20 (7) ◽  
pp. 4358-4363
Author(s):  
Jeung Hun Park ◽  
Richard S. Kim ◽  
Se-Jeong Park ◽  
Gye-Choon Park ◽  
Choong-Heui Chung
Keyword(s):  
Raman Spectroscopy ◽  
Dose Rate ◽  
Raman Spectra ◽  
Optical Phonon ◽  
Longitudinal Optical ◽  
Transverse Optical ◽  
Longitudinal Optical Phonon ◽  
Phonon Modes ◽  
Gaas Nanowires ◽  
Beam Dose

We report the relation between the catalyst patterning conditions and the intensity of the 1st order Raman active modes in Au-catalyzed GaAs nanowire bundles. We fabricated e-beam lithographically Au-patterned GaAs(111)B substrates by varying the patterning conditions (e-beam dose rate, dot-size and interdot-spacings), and grew GaAs nanowires via vapor–liquid–solid process using a solid-source molecular beam epitaxy. To understand the effects of the substrate preparation conditions and resulting morphologies on the optical characteristics of 1st order transverse optical and longitudinal optical phonon modes of GaAs, we characterized the nanowire bundles using complementary μ-Raman spectroscopy and scanning electron microscopy as a function of the e-beam dose rate (145–595 μC/cm2), inter-dot spacing (100 and 150 nm) and pattern size (100 and 150 nm). Ensembles of single crystalline GaAs nanowires covered with different Au-thickness exhibit a downshift and asymmetric broadening of the 1st order transverse optical and longitudinal optical phonon peaks relative to GaAs bulk modes. We also showed that the sensitivity of a downshift and broadening of Raman spectra are directly related to morphological and surface coverage variations in as-grown nanowires. We observed clear increases of the transverse optical and longitudinal optical intensity as well as the relatively higher peak shift and broadening of Raman spectra from the 100 nm patterning in response to the dose rate change. Strong dependence of Raman spectra of the nanowire bundles on the e-beam dose rate changes are attributed to the variations in spatial density, size, shape and random growth orientation of the wires. We have shown that the identification of the changes in GaAs longitudinal optical and Arsenic anti-site peaks is good indicators to characterize the quality of as-grown GaAs nanowires. Our finding confirms the utilization of Raman spectroscopy as a powerful tool for characterizing chemical, structural, and morphological information of as-grown nanowires within the supporting substrate.

Effects of two longitudinal optical‐phonon modes on electron distribution in GaxIn1−xAsyP1−y

1982 ◽  
Vol 40 (9) ◽  
pp. 836-838 ◽  
Author(s):  
Yoshikazu Takeda ◽  
M. A. Littlejohn ◽  
R. J. Trew ◽  
J. A. Hutchby
Keyword(s):  
Optical Phonon ◽  
Electron Distribution ◽  
Longitudinal Optical ◽  
Longitudinal Optical Phonon ◽  
Phonon Modes
Sign in / Sign up

Export Citation Format

Share Document