Superfluorescence of Sub-Band States in C-Plane In0.1Ga0.9N/GaN Multiple-QWs

Abstract

Superfluorescence is a collective emission from quantum coherent emitters due to quantum fluctuations. This is characterized by the existence of the delay time (τD) for the emitters coupling and phase-synchronizing to each other spontaneously. Here we report the observation of superfluorescence in c-plane In0.1Ga0.9N/GaN multiple-quantum wells by time-integrated and time-resolved photoluminescence spectroscopy under higher excitation fluences of the 267 nm laser and at room temperature, showing a characteristic τD from 79 ps to 62 ps and the ultrafast radiative decay (7.5 ps) after a burst of photons. Time-resolved traces present a small quantum oscillation from coupled In0.1Ga0.9N/GaN multiple-quantum wells. The superfluorescence is attributed to the radiative recombination of coherent emitters distributing on strongly localized subband states, Ee1→Ehh1 or Ee1→Elh1 in 3nm width multiple-quantum wells. Our work paves the way for deepening the understanding of the emission mechanism in the In0.1Ga0.9N/GaN quantum well at a higher injected carrier density.

Time distribution of stimulated transition probabilities

“…In the upper panel of figure 7 we show the optical response reported by Nakamura et al [43]. for the blue emitting In x Ga 1−x N/In y Ga 1−y N superlattice, and in panel (a) the theoretical calculation reported in [44], using the optical susceptibility in equation (30). Although the frequency distribution of the optical transitions are faithfully described, the lower wavelength peaks are much larger than the experimental ones.…”