Laser Heating, Refrigeration, and Thermometry of Semiconductor Nanomaterials

Book excerpt: Photothermal heating is a major constraint that limits the performance of many nanoscale optoelectronic and optomechanical semiconductor devices including nanolasers, optomechanical resonators, and integrated photonic circuits. Laser refrigeration of semiconductor devices to counteract photothermal heating has been a long-standing challenge. This work highlights the errors in previous experimental efforts and shows that the existing semiconductor laser refrigeration claims are controversial. It also presents an alternative route to experimentally achieve the laser refrigeration of a CdS nanoribbon (CdSNR) by >20 K, using Yb3+ doped LiYF4 microcrystal attached to it. Further, it explores the other promising avenues for achieving intrinsic laser refrigeration in wide band gap semiconductor materials, such as diamond, using color centers.