Conventional semiconducting nanowire optoelectronic devices generally exhibit low efficiency, due to dominant nonradiative surface recombination. Here, it is shown that such a critical challenge can be potentially addressed by exploiting structures in the deep-nanoregime. The epitaxy and structural optical characteristics of GaN-based micro-network nanostructures grown on Si wafer are studied. ...

The development of optical gain in chemically synthesized semiconductor nanoparticles (nanocrystal quantum dots) has been intensely studied as the first step toward nanocrystal quantum dot lasers. We examined the competing dynamical processes involved in optical amplification and lasing in nanocrystal quantum dots and found that, despite a highly efficient intrinsic nonradiative Auger recombina...

A heated semiconductor light-emitting diode at low forward bias voltage V<k(B)T/q is shown to use electrical work to pump heat from the lattice to the photon field. Here the rates of both radiative and nonradiative recombination have contributions at linear order in V. As a result the device's wall-plug (i.e., power conversion) efficiency is inversely proportional to its output power and diverg...

We propose a network rebonding model for light-induced metastability in amorphous silicon, involving bonding rearrangements of silicon and hydrogen atoms. Nonradiative recombination breaks weak silicon bonds and generates dangling bond-floating bond pairs, with very low activation energies. The transient floating bonds annihilate, generating local hydrogen motion. Charged defects are also found...

This paper discusses the potential of the intermediate band solar cell IBSC concept to improve the efficiency of thin-film chalcopyrite solar cells. The results show that solar cells based on CuGaS2, with a radiative limiting efficiency of 46.7%, exhibit the highest potential. A simple method for the identification of transition elements that when incorporated in CuGaS2 could possibly introduce...

We report experimental measurements and analysis of HOMO-LUMO transition photoluminescence and photoinduced bleaching magnitude and decay kinetics in lead sulfide quantum dots in glass. We find that the radiative lifetime is independent of temperature from 77K to 500K. The lifetime of the HOMO-LUMO state decreases dramatically for T>300K, indicating thermally activated nonradiative recombinatio...

We report on the thickness dependent laser cooling in CdS nanobelts pumped by a 532 nm green laser. The lowest achievable cooling temperature is found to strongly depend on thickness. No net cooling can be achieved in nanobelts with a thickness below 65 nm due to nearly zero absorption and larger surface nonradiative recombination. While for nanobelts thicker than ~120 nm, the reabsorption effe...

The efficiency of micro-light-emitting diodes (?-LEDs) depends enormously on the chip size, and this is connected to sidewall-trap-assisted nonradiative recombination. It known that internal quantum (IQE) aluminum gallium indium phosphide (AlGaInP)-based red ?-LEDs much lower than nitride-based ?-LEDs. To establish major reasons giving rise huge IQE discrepancy, we examined limiting factors in ...

Charge carriers trapped at localized surface defects play a crucial role in quantum dot (QD) photophysics. Surface traps offer longer lifetimes than band-edge emission, expanding the potential of QDs as nanoscale light-emitting excitons and qubits. Here, we demonstrate that nonradiative plasmon mode drives transfer from two-photon-excited to trap states. In plasmonic cavities, emission dominate...