Based on time-resolved electroluminescence (TREL) measurement, more efficient carrier injection, transport, relaxation, and recombination associated with a stronger carrier localization and a low polarization effect in a nonpolar m-plane InGaN/GaN light emitting diode (m-LED), compared with those in a polar c-LED, are reported. With a higher applied voltage in the c-LED, decreasing response tim...

We demonstrate that electron spin relaxation in GaAs in the proximity of a Fe/MgO layer is dominated by interaction with an exchange-driven hyperfine field at temperatures below 60 K. Temperature-dependent spin-resolved optical pump-probe spectroscopy reveals a strong correlation of the electron spin relaxation with carrier freeze-out, in quantitative agreement with a theoretical interpretation...

Colloidal quantum dots (QDs) have attracted interest as materials for opto-electronic applications, wherein their efficient energy use requires the understanding of carrier relaxation. In QDs capped by bifunctional thiols, used to attach the QDs to a surface, the relaxation is complicated by carrier traps. Using 2D spectroscopy at 77 K, we follow excitations in thiol-capped CdSe QDs with state ...

We have compared the time integrated photoluminescence ~PL! and the time resolved PL of several lattice matched InGaAs/InP quantum wells intermixed either by ion implantation or an impurity-free method. We have found that the carrier capture rates into quantum wells and carrier relaxation from the wells depend on the type of intermixing used. Our results indicate that the carrier lifetimes are ...

An improved multivalley hydrodynamic model (HDM) including realistic band structure effects and impact ionization is developed. Unlike the recently-proposed HDM by Thoma et al [1] for nonparabolic band structures, our model minimizes the number of relaxation times and includes impact ionization. Furthermore, the intervalley transitions of hot carriers are considered. Also, the momentum relaxati...

This paper presents a laser model for describing the effects of nonequilibrium carrier distributions. The approach is based on the coupled Maxwell-semiconductor-Bloch equations, with carrier–carrier and carrier–phonon collisions treated in the relaxation rate approximation. Using examples involving relaxation oscillation, current modulation, and optical injection, we demonstrate how the model c...

In this study we investigate the carrier relaxation dynamics in p-type doped InGaAs/GaAs quantum dots using time-integrated and time-resolved photoluminescence. The experiment shows that while a strong phonon bottleneck is observed in the undoped samples, with a 680 ps rise time of the photoluminescence intensity, the intra-dot relaxation time (31 ps) of the p-type doped samples is reduced sign...

A typical signature of charge extraction in disordered organic systems is dispersive transport, which implies a distribution of charge carrier mobilities that negatively impact on device performance. Dispersive transport has been commonly understood to originate from a time-dependent mobility of hot charge carriers that reduces as excess energy is lost during relaxation in the density of states...