Non-contact luminescence thermometer based on upconversion emissions from Er3+-doped beta-Ga2O3 with wide bandgap

Abstract

The beta-Ga2O3 with wide bandgap is an important semiconductor for optoelectronic applications. In this work, the Er3+-doped beta-Ga2O3 with upconversion emissions has been prepared for optical thermometry. The upconversion emission spectra include green bands around 522 and 554 nm, red emission band around 654 nm by a 980 nm laser excitation. A luminescence thermometer is constructed with the emission intensity ratio of the 2H11/2 → 4I15/2 and 2S3/2 → 4I15/2 transitions in Er3+ ions. The maximal relative and absolute sensitivities were 1.08% and 3.56 × 10−3 K−1, respectively. This work indicates that Er3+ doped beta-Ga2O3 could be a promising optical thermometer in integrated optoelectronics.