Suppressing nonradiative deactivation of charge transfer (CT) states is pivotal to realizing further improvements in the power conversion efficiencies polymer solar cells (PSCs). According energy gap law, decay rate constant knr scales exponentially with decreasing CT state ECT; thereby, as long governed by a decrease ECT will inevitably increase and hence efficiency. Here, we report dynamics g...

Compact ultraviolet light sources are currently of high interest for a range of applications, including solid-state lighting, short-range communication, and bio-chemical detection. We report on the design and analysis of AlGaN-based lightemitting diodes with an emission wavelength near 280 nm. Internal device physics is investigated by threedimensional numerical simulation. The simulation incor...

We study the excitonic recombination dynamics in an ensemble of (9,4) semiconducting single-wall carbon nanotubes by high-sensitivity time-resolved photoluminescence experiments. Measurements from cryogenic to room temperature allow us to identify two main contributions to the recombination dynamics. The initial fast decay is temperature independent and is attributed to the presence of small re...

The kinetics of indirect photoluminescence of GaAs/AlxGa12xAs double quantum wells, characterized by a random potential with a large amplitude ~the linewidth of the indirect photoluminescence is comparable to the binding energy of an indirect exciton! in magnetic fields B<12 T at low temperatures T>1.3 K is investigated. It is found that the indirectrecombination time increases with the magneti...

Exponential blinking statistics was reported in oxidized Si nanoparticles and the switching mechanism was attributed to the activation and deactivation of unidentified nonradiative recombination centers. Using ab initio calculations we predicted that Si dangling bonds at the surface of oxidized nanoparticles introduce defect states which, depending on their charge and local stress conditions, m...

InAs quantum-dot (QD) lasers were investigated in the temperature range 20–300 K and under hydrostatic pressure in the range of 0–12 kbar at room temperature. The results indicate that Auger recombination is very important in 1.3m QD lasers at room temperature and it is, therefore, the possible cause of the relatively low characteristic temperature observed, of 0 = 41 K. In the 980-nm QD lasers...

Cathodoluminescence (CL) imaging and spectroscopy have been used to characterize fully strained SiGe quantum wells grown on Si. At T-5 K, the CL spectra contain only band edge luminescence features. Monochromatic imaging with the no-phonon line attributed to the bound excitons in the quantum well, has shown that the distribution of the luminescence from the wells is not uniform. The thinnest we...