Study on photoluminescence characteristics and whispering gallery mode resonance from Cr doped CuGaO2 nanoplates

Abstract In this study, Cr doped hexagonal CuGaO2 (CGO) nanoplates (NPs) are fabricated successfully. It is worth noting that an emission band located at approximately 700 nm has been found in the photoluminescence (PL) spectrum of CuGa 1−x Cr x O2 NPs, which can be ascribed to the deep levels emission caused by the Cr 3d and 4s states. Moreover, six resonance peaks also appear in the PL spectrum, which prove that resonance is formed in CGO NPs cavity. The resonant process and resonance mode were investigated in experiment and theory. As the consequence, mode spacing is approximately 8.5 nm and the mode numbers are 60, 59, 58, 57, 56 and 55 corresponding to the peaks of 691 nm, 699 nm, 707 nm, 715 nm, 723 nm and 731 nm in the PL spectrum. The finite difference time domain (FDTD) solution is also used to study resonance mechanism of CGO NPs. These results reveal that the mode calculations and FDTD simulations well agree with the experimental data. The present work further improves the potential applications of CuGa 1−x Cr x O2 NPs in the field of optoelectronic devices.