Optical studies in Cr-doped beta-Ga2O3, ZnGa2O4, and Zn1-xGa2-2xGexO4

Wide and ultrawide bandgap oxides, such as β-Ga2O3, ZnGa2O4 and Zn1-xGa2-2xGexO4, are of particular importance for a myriad of technological applications, including electronics, optoelectronics, and medical devices. In the case of the latter, the development of new, affordable and non-invasive methodologies for bioimaging and diagnosis is of crucial importance towards solutions that can improve health and wellbeing of the populations. For these purposes, red/near infrared emitters within the biological transparency window are required. Therefore, the here studied oxides were subjected to a controlled Cr-doping giving rise to intraionic emission in this region. In the case of the here studied oxide systems, we will investigate the intraionic luminescence properties of Cr3+, with particular emphasis on the persistent luminescence recorded in micro/nano particles of Cr-doped ZnGa2O4 and Zn1-xGa2-2xGexO4 synthesised by laser ablation in liquid media.