We have examined the kinetics of carrier relaxation in GaAs/AlGaAs quantum wells ~QWs!, quantum wires ~QWRs!, and quantum boxes ~QBs! with time-resolved cathodoluminescence ~CL!. In the cases of QWRs and QBs, the nanostructures were grown via a size-reducing growth approach on pre-patterned GaAs~001! substrates composed of stripes and mesas, respectively. The growth involved deposition of multi...

Abstract Electron spins in gate-defined quantum dots (QDs) formed semiconductor wells (QWs) are promising stationary qubits for implementing large-scale networks a scalable manner. One key ingredient such network is an efficient photon–spin interface that converts any polarization state of flying photonic qubit to the corresponding electron QDs. A bull’s-eye cavity optical structure can enhance...

The nearly lattice-matched InxGa1−xN/InyAl1−yN epi-layers were grown on a GaN template by plasma-assisted molecular beam epitaxy with metal modulation technique. band-gap energy of InxGa1−xN QW in photoluminescence measurement was estimated to be 2.89 eV and the indium concentration (x) 14.8%. In X-ray photoelectric spectroscopy, we obtained an (y) InyAl1−yN barrier 25.9% band-offset 4.31 eV. F...

In this paper, we study the hydrogen-like donor-impurity binding energy of ground-state change as a function well width under effect temperature, size, and impurity position. Within framework effective mass approximation, Schrodinger-Poisson equation has been solved taken account an on-center in double QWs with rectangular finite confinement potential profile for 10% indium concentration (well ...

The control of inverters has degrees freedom that open the way to improve output harmonic spectrum. Numerous works dealing with this objective have been proposed in literature, particularly within definition switching angles. Among them, well-known PWM techniques such as Quarter Wave Symmetry (QWS), Half (HWS), and Full (FWS) are based on Optimal Pulse Patterns (OPP) computation using symmetrie...

GaN-based materials are well-recognized for their exceptional optical qualities, particularly in the blue and UV parts of the spectrum. In addition, their wide bandgaps allow efficient operation at room temperature and higher. This work will describe the room-temperature performance of optically-pumped GaN photonic crystal (PC) nanobeam lasers, with thresholds as low as 9.1 μJ/cm2, the lowest r...

GaN-based blue laser diodes (LDs) may exhibit anomalous temperature characteristics such as a very high characteristic temperature (T 0) or even negative T 0. In this work, temperature-dependent characteristics of GaN-based blue LDs with InGaN double quantum well (QW) structures were investigated using numerical simulations. The temperature-dependent threshold current is found to become increas...

We report the optical measurement of the spin dynamics at elevated temperatures and in zero magnetic field for two types of degenerately doped n-InSb quantum wells (QWs), one asymmetric (sample A) and one symmetric (sample B) with regards to the electrostatic potential across the QW. Making use of three directly determined experimental parameters: the spin lifetime, τ(s), the sheet carrier conc...

The effect of interface intermixing in W-design GaSb/AlSb/InAs/Ga0.665In0.335AsxSb1 - x/InAs/AlSb/GaSb quantum wells (QWs) has been investigated by means of optical spectroscopy supported by structural data and by band structure calculations. The fundamental optical transition has been detected at room temperature through photoluminescence and photoreflectance measurements and appeared to be bl...

Data are presented showing that, besides the improvement in carrier collection, it is advantageous to locate strain-matching auxiliary InGaAs layers @quantum wells ~QWs!# within tunneling distance of a single-quantum-dot ~QD! layer of an AlGaAs–GaAs–InGaAs–InAs QD heterostructure laser to realize also smaller size QDs of greater density and uniformity. The QD density is changed from 2310/cm for...