Investigation of upconversion and photoacoustic properties of NIR activated Er3+/Yb3+ doped [RE]VO4 (RE = Y, Gd) phosphors for photothermal conversion applications

Er3+/Yb3+ doped YVO4 and GdVO4 phosphors were prepared through the combustion technique and were characterized through various techniques. XRD has revealed a tetragonal structure for YVO4 and GdVO4 phosphors. The 980 nm excited upconversion emission has resulted in intense green upconversion emission from both samples. However, the GdVO4 sample has shown higher emission intensity. Photoacoustic heat generation in samples has been studied using the same 980 nm excitation, and in this case, the YVO4 phosphor has shown higher heat generation. The YVO4 phosphor again has shown lower heat dissipation and, hence, higher photo-thermal conversion efficiency upon irradiation of the sample.