Carrier localization in a random band potential is known to determine luminescence and lasing properties of visible-range InGaN-based light emitters. In this work, we study related effects in indium-rich InGaN ternary alloys with the near-infrared range spectral response. The investigated samples feature strong n-type residual doping inherent to InN, and we exploit this fact to perform all-optical characterization of the valence band tail states. Non-thermal hole distribution emerging at low temperatures is revealed, using time-resolved photoluminescence. A consistent model is proposed, which explains the observed strong red shift of the stimulated emission wavelength with respect to the spontaneous emission and luminescence quenching behavior at the increasing temperature.

K.Kudryavtsev, B.Andreev, D.Lobanov, M.Kalinnikov, A.Novikov, Z.Krasilnik
JETP Letters 121, issue 8 (2025)