| Summary: | Superfluorescence is a collective emission from quantum coherent emitters due to quantum fluctuations. This is characterized by the existence of the delay time (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>τ</mi><mi>D</mi></msub><mo stretchy="false">)</mo></mrow></semantics></math></inline-formula> for the emitters coupling and phase-synchronizing to each other spontaneously. Here we report the observation of superfluorescence in c-plane In<sub>0.1</sub>Ga<sub>0.9</sub>N/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 <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>τ</mi><mi>D</mi></msub></mrow></semantics></math></inline-formula> 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 In<sub>0.1</sub>Ga<sub>0.9</sub>N/GaN multiple-quantum wells. The superfluorescence is attributed to the radiative recombination of coherent emitters distributing on strongly localized subband states, <i>E<sub>e</sub></i><sub>1</sub>→<i>E<sub>hh</sub></i><sub>1</sub> or <i>E<sub>e</sub></i><sub>1</sub>→<i>E<sub>lh</sub></i><sub>1</sub> in 3nm width multiple-quantum wells. Our work paves the way for deepening the understanding of the emission mechanism in the In<sub>0.1</sub>Ga<sub>0.9</sub>N/GaN quantum well at a higher injected carrier density.
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