Microwave‐assisted synthesis of erbium‐doped yttrium oxide nanoparticles and their upconversion properties

Abstract

A time‐ and energy‐saving microwave (MW)‐assisted method was adopted to synthesise yttrium oxide (Y 2 O 3 ):erbium (Er) nanoparticles with upconversion (UC) luminescence properties within a few minutes, followed by a post‐calcination treatment. It was demonstrated that calcination of nanoparticles at 800°C fully removed the organic groups from them and consequently produced crystalline Y 2 O 3 nanoparticles, which was evident from X‐ray diffraction (XRD) and Fourier transform infrared analysis. The energy‐dispersive X‐ray spectroscopy and XRD analysis confirmed that the Er element was successfully doped in Y 2 O 3 nanoparticles. The growth process was monitored by time‐dependent experiments, during which ultra‐small particles would form first and then gradually dissolved and re‐growed on surfaces of big particles. A two‐photon process was demonstrated in the fabricated Y 2 O 3 :Er nanoparticles. As a cost‐effective and highly‐efficient method, the MW method can facilitate mass production and further application of UC nanomaterials into a variety of fields including solar cells, flat panel displays, sensors and UC lasers.