A GaInP/AlGaInP multiple quantum well laser structure was grown by low-pressure metalorganic chemical vapor deposition with tertiarybutylarsine and tertiarybutylphosphine. Laser diodes fabricated from this structure lased at room temperature. Photoluminescence ~PL! measurements were performed from 10 to 230 K. The PL energy increased with temperature from 10 to 70 K and decreased above 70 K. Th...

Time-resolved optical characterization is an indispensable tool to study the recombination mechanisms of excitons and/or carriers based on radiative, non-radiative, localization and many-body processes. In this paper, we review the instrumentation of various spectroscopic techniques for the assessment of InxGa1– xN-based semiconductors such as time-resolved photoluminescence (TRPL), time-resolv...

The spontaneous electroluminescence emission of InAs light-emitting diodes ~LEDs! operating at 3.3 mm was studied as a function of applied hydrostatic pressure. An enhancement of a factor of almost four in radiative efficiency at room temperature was observed in the range 0 to 10 kbar. Analysis of the dependence of electroluminescence emission intensity on hydrostatic pressure at constant curre...

We use single self-assembled InGaAs quantum dots as internal probes to map the local density of optical states of photonic crystal membranes. The employed technique separates contributions from nonradiative recombination and spin-flip processes by properly accounting for the role of the exciton fine structure. We observe inhibition factors as high as 70 and compare our results to local density ...

We discuss a THz laser device based on a semiconductor quantum dot (QD) gain medium, where the lasing occurs through discrete conduction states. An ensemble of QDs is selectively placed in a high quality cavity, called a microdisk, which is resonant with a terahertz intersublevel QD transition. We simulate the rate equations goveming iasing and discuss a variety of processes affecting lasing in...

The research group at Columbia University investigated carrier dynamics in SWNTs in micellar solution. They found that nonradiative Auger recombination is an important mechanism of fluorescence quenching in SWNTs. At low pH, nanotube surface endoperoxides protonate and introduce holes that quench the luminescence. In order to characterize electronic structure of SWNTs at the single-tube level, ...

One of the most challenging aspects semiconductor nanotechnology is presence extremely efficient nonradiative decay pathways (known as Auger processes) that hinder any attempt at creating population inversion and obtaining gain in nanocrystals. What even more frustrating that, cases, strategies adopted to slow down these nanostructures also lead a comparable increase radiative recombination tim...

Dynamics of a low-density exciton system is simulated using the kinetic Monte Carlo algorithm. The temperature dependences photoluminescence (PL) intensity and PL band Stokes shift in high-Al-content AlGaN epi­layer are calculated fitted to experimentally measured ones. key features nonradiative recombination via delocalized states direct tunnelling centres their influence on efficiency analyse...