Photoluminescence Study of Suspended MQW Structures for Laser Refrigeration Purposes

Suspended semiconductor structures with high thermal isolation provide high temperature sensitivity of the dissipated thermal power. Therefore they can be used to obtain essential information about the underlying mechanisms of anti-Stokes laser cooling. Here, we experimentally investigate the electron-hole pair recombination processes in suspended and non-suspended MQW structures from 77 K up to room temperature. Excitation dependent and time-resolved micro-photoluminescence measurements have been used to conduct this study. To include the effects of lateral carrier diffusion, we preformed finite-element time-resolved analysis of carrier recombination and diffusion and thermal transients. The potential of these structures for laser cooling purposes is discussed.