Carrier-carrier relaxation kinetics in quantum well semiconductor structures with nonparabolic energy bands

Carrier-carrier relaxation kinetics in quantum well semiconductor structures with nonparabolic energy bands

Dependence of the photoluminescence energy and carrier lifetime of the carrier density in nitride quantum well

We investigated the high-carrier screening of macroscopic polarization fields in GaN quantum wells (QWs) using a variational wave function for electrons and holes. In particular, we studied of the influence of free-carrier screening on the photoluminescence (PL) energy emission and carrier lifetime in the QW. We show that the energy transition between electrons and holes are explained well by t...

Carrier relaxation and recombination in an InGaN/GaN quantum well probed with time-resolved cathodoluminescence

Spatially, spectrally, and temporally resolved cathodoluminescence ~CL! techniques have been employed to examine the optical properties and kinetics of carrier relaxation for metalorganic chemical vapor deposition grown InGaN/GaN single quantum wells ~QWs!. Cathodoluminescence wavelength imaging of the QW sample revealed local band gap variations, indicating the presence of local In composition...

Intersubband relaxation dynamics in semiconductor quantum structures

We monitor the temporal evolution of the electron population in the first and second subband of an undoped GaAs/AlGaAs asymmetric double quantum well after interband optical excitation by using an interband pump/intersubband probe technique. The spacing between the two subbands is smaller than the longitudinal optical phonon energy. We extract an intersubband lifetime of T21 = 100 ps and a reco...

Exciton condensate in semiconductor quantum well structures.

We propose that the exciton condensate may form in a well-controlled way in appropriately arranged semiconductor quantum well structures. The mean-field theory of Keldysh and Kopaev, exact in both the high density and the low density limits, is solved numerically to illustrate our proposal. The electron-hole pairing gap and the excitation spectrum of the exciton condensate are obtained. The ene...