Optical Properties of CdZnS-ZnS Strained-Layer Superiattices

1989 ◽  
Vol 161 ◽  
Author(s):  
Yasuyuki Endoh ◽  
Tsunemasa Taguchi
Keyword(s):  
Stark Effect ◽  
Quantum Confinement Effect ◽  
Peak Position ◽  
Alloy Layer ◽  
Exciton Peak ◽  
Strained Layer ◽  
Quantum Confined Stark Effect ◽  
Low Pressure Mocvd ◽  
Strained Layer Superlattices ◽  
First Time

ABSTRACTThe Cd0.3 Zn0.7S-ZnS strained-layer superlattices has for the first time been fabricated on (100)GaAs substrates by a low-pressure MOCVD method. Exciton luminescence properties were investigated by the photoluminescence spectroscopies which show that the quantum confinement effect of excitons occurs in the CdZnS alloy layer. Temperature dependence of the exciton properties reveals a dominant scattering process which originates from exciton-phonon interaction(Γ10 =68meV). Nevertheless, the large exciton binding energy of about 166meV makes it possible to produce the exciton peak at room temperature. The effect of external electric field on the exciton intensity and its peak position is found and is tentatively interpreted in terms of a quantum confined Stark effect.

Nonpolar/Semipolar GaN Technology for Violet, Blue, and Green Laser Diodes

MRS Bulletin ◽  
2009 ◽  
Vol 34 (5) ◽  
pp. 324-327 ◽  
Author(s):  
Hiroaki Ohta ◽  
Kuniyoshi Okamoto
Keyword(s):  
Stark Effect ◽  
Optical Pumping ◽  
Laser Diodes ◽  
Wavelength Region ◽  
Green Laser ◽  
Research Field ◽  
Light Emitting ◽  
Quantum Confined Stark Effect ◽  
Semipolar Gan ◽  
First Time

AbstractTo achieve 520–532 nm green laser diodes (LDs), nonpolar and semipolar nitrides have attracted much attention because their usage leads to the elimination of the quantum-confined Stark effect and higher optical gains in this wavelength region. Since the breakthrough in the homoepitaxial growth technology for them, many nonpolar m -plane devices such as mW-class blue light-emitting diodes, violet 405 nm LDs, blue 460 nm LDs, and blue-green LDs beyond 490 nm have been announced. Advantages such as small blueshift and high slope efficiency (high output power to injected current ratio) have been confirmed for the first time in m -plane LDs beyond the blue region. On the other hand, the semipolar plane is also a candidate for green LDs. The pulsed operation of semipolar (1011) and (1122) violet LDs and lasing for a (1122) LD at 514 nm by optical pumping also have been reported. Such rapid progress in this research field will be reviewed.

New Relaxation Mechanism in Short Period Si/Ge Strained-Layer Superlattices

1990 ◽  
Vol 183 ◽  
Author(s):  
Werner Wegscheider ◽  
Karl Eberl ◽  
Gerhard Abstreiter ◽  
Hans Cerva ◽  
Helmut Oppolzer
Keyword(s):  
Activation Barrier ◽  
Relaxation Mechanism ◽  
Layer Growth ◽  
Lattice Imaging ◽  
Strained Layer ◽  
Partial Dislocations ◽  
Transmission Electron ◽  
Short Period ◽  
Strained Layer Superlattices ◽  
First Time

AbstractHigh quality Si/Ge strained-layer superlattices composed of a sequence of alternating 3 monolayers pure Si and 9 monolayers pure Ge have been grown by molecular beam epitaxy at 310°C on Ge(001) substrates. In order to investigate the transition from coherent to incoherent growth in these tensily strained structures a set of samples with varying number of superlattice periods has been studied by transmission electron microscopy. It is found that superlattices as thick as 33 nm at least show perfect and defect-free layer growth whereas for thicker superlattices strain accommodation occurs. For this strained heteroepitaxial system we observed, to our knowledge, for the first time the formation of microtwins as the only relaxation mechanism. High-resolution lattice imaging reveals that the twin lamellae result from successive glide of 90° (a/6)<112> Shockley partial dislocations on adjacent {111} planes from the surface towards the bulk. The activation barrier which has to be overcome in the case of 90° partial dislocations is compared with the energies required for the nucleation of 60° perfect and 30° partial misfit dislocation half-loops.

Faceted growth of ({\bf {\overline 1}103})-oriented GaN domains on an SiO2-patterned m-plane sapphire substrate using polarity inversion

2017 ◽  
Vol 50 (1) ◽  
pp. 30-35 ◽  
Author(s):  
Hansub Yoon ◽  
Miyeon Jue ◽  
Dongsoo Jang ◽  
Chinkyo Kim
Keyword(s):  
Sapphire Substrate ◽  
Stark Effect ◽  
Heteroepitaxial Growth ◽  
Lower Growth ◽  
Polarity Inversion ◽  
Quantum Confined Stark Effect ◽  
Quantum Confined ◽  
Dominant Configuration ◽  
Semipolar Gan ◽  
First Time

Heteroepitaxial growth of ({\overline 1}103)-oriented GaN domains on m-plane sapphire is energetically unfavourable in comparison with that of (1{\overline 1}0{\overline 3})-oriented GaN domains, but the faceted domains with ({\overline 1}103)-oriented GaN reveal a more m-facet-dominant configuration than (1{\overline 1}0{\overline 3})-oriented GaN in such a way that the quantum-confined Stark effect can be more effectively suppressed. It is reported here, for the first time, that semipolar ({\overline 1}103)-oriented and faceted GaN domains can be grown on an SiO2-patterned m-plane sapphire substrate by employing polarity inversion of initially nucleated (1{\overline 1}0{\overline 3})-oriented GaN domains. This polarity inversion of semipolar GaN was found to occur when the domains were grown with a 20–37.5 times higher V/III ratio and 70 K lower growth temperature than corresponding parameters for polarity-not-inverted domains. This work opens up a new possibility of effective suppression of the quantum-confined Stark effect by polarity-controlled semipolar GaN in an inexpensive manner in comparison with homoepitaxial growth of ({\overline 1}103)-oriented GaN on a GaN substrate.

Si-Ge STRAINED LAYER SUPERLATTICES

1987 ◽  
Vol 48 (C5) ◽  
pp. C5-321-C5-327 ◽  
Author(s):  
H. BRUGGER ◽  
G. ABSTREITER
Keyword(s):  
Strained Layer ◽  
Strained Layer Superlattices

Multicanonical Molecular Dynamics Simulation Study of the Liquid-Solid and Solid-Solid Transitions in Lennard-Jones Clusters

2011 ◽  
Author(s):  
Toshihiro Kaneko ◽  
Kenji Yasuoka ◽  
Ayori Mitsutake ◽  
Xiao Cheng Zeng
Keyword(s):  
Molecular Dynamics ◽  
Heat Capacity ◽  
Transition Temperature ◽  
Peak Position ◽  
Temperature Curve ◽  
Dynamics Simulation ◽  
Lennard Jones ◽  
Dynamics Simulations ◽  
First Time ◽  
Good Agreement

Multicanonical molecular dynamics simulations are applied, for the first time, to study the liquid-solid and solid-solid transitions in Lennard-Jones (LJ) clusters. The transition temperatures are estimated based on the peak position in the heat capacity versus temperature curve. For LJ31, LJ58 and LJ98, our results on the solid-solid transition temperature are in good agreement with previous ones. For LJ309, the predicted liquid-solid transition temperature is also in agreement with previous result.

O-band GeSi quantum-confined Stark effect electro-absorption modulator integrated in a 220nm silicon photonics platform

2020 ◽  
Author(s):  
Clement Porret ◽  
Srinivasan Ashwyn Srinivasan ◽  
Sadhishkumar Balakrishnan ◽  
Peter Verheyen ◽  
Paola Favia ◽  
...  
Keyword(s):  
Silicon Photonics ◽  
Stark Effect ◽  
Quantum Confined Stark Effect ◽  
Quantum Confined
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