Upconversion luminescence properties of Ga2O3: Yb3+, Er3+ nanoparticles: Effects of calcination temperature and dopant concentration

Fluorides despite been the most widely studied host matrices for many upconversion nanoparticles are usually hygroscopic and are of limited use. Hence, explorations of new upconversion host materials that will be more efficient in practical application are still active areas of research. In this study, applicability of Ga2O3 as a host matrix for upconversion luminescence was investigated under near infrared (980 nm) excitation. XRD and FT-IR analysis indicate that changes in the calcination temperature and dopant ion concentration lead to crystal phase transformation of nanoparticles from β-Ga2O3 to cubic Yb3Ga5O12 garnet. Resulting changes in crystal field and sites symmetries alter the behaviour of upconversion. Accordingly, tunable green, red and infrared luminescences were observed.