InGaN quantum dots grown by metalorganic vapor phase epitaxy employing a post-growth nitrogen anneal
APPLIED PHYSICS LETTERS 83:4 (2003) 755-757
Dynamics and gain in highly-excited InGaN MQWs
Current Applied Physics 2:4 (2002) 321-326
Abstract:
The Kerr gate technique is used to time-resolve the gain in an In0.02Ga0.98N/In0.16Ga0.84N multiple quantum well sample. A new way of analyzing the data in such a variable stripe length method gain experiment is used to analyze both the time-integrated and time-resolved spectra. We confirm that the stripe length dependence of the gain in the multiple quantum wells under nanosecond excitation is caused by the change of the chemical potential along the excited stripe due to the interaction of the carrier and photon densities, and the gain threshold density is estimated. A trial function assuming a Lorentzian line shape for the stripe length dependence of the gain is compared with the edge emission intensity. This is found to fit very well with our data, even beyond the saturation region. Furthermore, we have extended the investigation to examine the dynamics of the emission and gain. These measurements suggest that the photoexcited carriers must localize (possibly at indium-rich sites) before strong stimulated emission is seen. © 2002 Elsevier Science B.V. All rights reserved.Dynamics and gain in highly-excited InGaN MQWs
CURR APPL PHYS 2:4 (2002) 321-326
Abstract:
The Kerr gate technique is used to time-resolve the gain in an In0.02Ga0.98N/In0.16Ga0.84N multiple quantum well sample. A new way of analyzing the data in such a variable stripe length method gain experiment is used to analyze both the time-integrated and time-resolved spectra. We confirm that the stripe length dependence of the gain in the multiple quantum wells under nanosecond excitation is caused by the change of the chemical potential along the excited stripe due to the interaction of the carrier and photon densities, and the gain threshold density is estimated. A trial function assuming a Lorentzian line shape for the stripe length dependence of the gain is compared with the edge emission intensity. This is found to fit very well with our data, even beyond the saturation region. Furthermore, we have extended the investigation to examine the dynamics of the emission and gain. These measurements suggest that the photoexcited carriers must localize (possibly at indium-rich sites) before strong stimulated emission is seen. (C) 2002 Elsevier Science B.V. All rights reserved.Coherent exciton-biexciton dynamics in GaN
Physical Review B - Condensed Matter and Materials Physics 65:19 (2002) 1931021-1931024
Abstract:
Spectrally resolved and time-integrated four-wave mixing are used to measure the polarization dependence of biexcitonic signals and quantum beats between two-A-exciton (XAXAZ*) and A-biexciton (XAXA) states in a high-quality GaN epilayer. Mixed beats with two periods are observed: the first beating period corresponds to the energy splitting between XAXA*and XAXA; the second period corresponds to beating between A excitons (XA) and donor bound excitons (DOX). We also measure the polarization-dependent B-biexciton (XBXB) signal. The effective masses for the A and B holes are deduced from the binding energy.Coherent Exciton-Biexciton Dynamics in GaN
Physical Review B: Condensed Matter and Materials Physics 65 (2002) 193102 4pp