Temperature stability of intersubband transitions in AlN/GaN quantum wells

TL;DR

This study investigates how intersubband transitions in AlN/GaN quantum wells are affected by temperature, showing minimal energy decrease up to 400°C through experimental absorption measurements and theoretical modeling.

Contribution

It provides combined experimental and theoretical analysis of temperature effects on intersubband transitions in AlN/GaN quantum wells, highlighting their stability at high temperatures.

Findings

Interband transition energy decreases by only ~6 meV at 400°C.

Temperature effects on band-gap and piezoelectric field are modeled.

Experimental and theoretical results are in good agreement.

Abstract

Temperature dependence of intersubband transitions in AlN/GaN multiple quantum wells grown with molecular beam epitaxy is investigated both by absorption studies at different temperatures and modeling of conduction-band electrons. For the absorption study, the sample is heated in increments up to $400^\circ$C. The self-consistent Schr\"odinger-Poisson modeling includes temperature effects of the band-gap and the influence of thermal expansion on the piezoelectric field. We find that the intersubband absorption energy decreases only by $\sim 6$ meV at $400^\circ$C relative to its room temperature value.