0000000000194228
AUTHOR
Yung-chen Cheng
showing 3 related works from this author
Carrier localization effect in polarized InGaN multiple quantum wells
2005
Carrier localization effects in polarized InGaN/GaN multiple quantum wells (MQWs) were investigated as a function of well width, d, and In content, x. Using photoreflectance (PR), photoluminescence (PL), PL excitation (PLE), selective excitation of PL, PL excitation power, and time-resolved PL spectroscopy, the dominance of the localization effect against the built-in field effect on carrier recombination dynamics in InxGa1–xN MQWs of different well width (d = 2.0–4.0 nm, x ≈ 0.15) and In content (x ≈ 0.22–0.27, d = 2.5 nm) was revealed. Based on the modeling of the PL spectra by Monte Carlo simulation of exciton hopping and the spectroscopic reference provided by PR, increased In content a…
Monte Carlo simulation approach for a quantitative characterization of the band edge in InGaN quantum wells
2005
Monte Carlo simulation approach based on exciton hopping through randomly distributed localized states is proposed for quantitative characterization of the band edge of InxGa1–xN/GaN multiple quantum wells with different indium content (x ≈ 0.22–0.27). The band edge dynamics is investigated in the 10–300 K range by analyzing the measured S- and W-shaped temperature behavior of the photoluminescence peak position and linewidth, respectively. The simulation of the W-shaped temperature dependence using double-scaled potential profile model enabled us to estimate the scale of the potential fluctuations due to variation of indium content inside and among In-rich regions formed in InGaN alloy. In…
Exciton hopping inInxGa1−xNmultiple quantum wells
2005
The dynamics of photoexcited excitons in thin $\mathrm{In}\mathrm{Ga}\mathrm{N}∕\mathrm{Ga}\mathrm{N}$ multiple quantum wells (QW's) with different In contents was studied by comparing the experimental data obtained by photoluminescence (PL), PL excitation, and photoreflectance spectroscopy techniques with the results of Monte Carlo simulations of exciton hopping. The temperature dependence of the PL linewidth was demonstrated to be in a fair agreement with the model of phonon-assisted exciton in-plane hopping within In-rich regions with inhomogeneous broadening taken into account. The band potential fluctuations, which scale the dispersion of localized states the excitons are hopping over,…