Observation of lattice thermal waves interference by photoluminescence blinking of InGaN quantum well devices

Abstract

The photoluminescence of III-V wide band-gap semiconductors as InGaN is characterized by local intensity fluctuations, known as 'blinking points', that despite decades of research are not yet completely understood. In this letter we report experimental data and a theoretical interpretation that suggests they are caused by the interference of thermal vibrations of the Quantum Well lattice. With far-field optical tests we could observe the lower frequency tail of these interference waves and study their dynamics as they propagate up to distances of several tens of microns.

The influence of water and ethanol adsorption on the optical blinking in InGaN quantum wells

“…However, this cannot explain the experimentally observed intensity distribution of the blinking [1,12]. Later, it was proposed that the interference of thermal vibration of the crystal lattice may be the cause of the unstable blinking [13]. However, this idea considers local phenomena and does not concern the external species present on the sample surface.…”

The relation between optical instabilities and absorbed material in photoluminescence with [0001] InGaN single quantum well

“…In InGaN SQW, instability blinking arises around a QD in a region of few µm of diameter and the flashing intensity width is temperature dependent [22]. Therefore, the phenomenon was associated to beating of slightly different thermal wave vibration creating unstable optical blinking [23]. On the other side, the so called optical memory effect was first found in the GaN epitaxial film [9,24].…”