Intense red-emitting multi-rare-earth doped nanoparticles of YVO4 for spectrum conversion towards improved energy harvesting by solar cells

Abstract

Yttrium vanadate nano-particles doped with single and multi ions (Sm3+, Eu3+, Bi3+) have been successfully synthesized at room temperature by optimized co-precipitation method. Doped orthovanadate forms monophasic nanocrystals in the 10–50 nm size range. Photoluminescence (PL) excitation shows broad band in the range 250–350 nm due to vanadate absorption and sharp peaks in the range of 390–470 nm due to f–f transitions of Sm3+/Eu3+ and emission in intense red/orange (614, 645, 699 nm). The nanoparticles can efficiently convert UV and blue photons (250–470 nm) to intense red and orange light that can be harnessed by both Si and dye sensitized solar cells for photovoltaic conversion. PL and time-resolved decay suggest that excitation and charge transfer between host, dopant and co-dopants play a profound role in the photophysical processes of multi-ion doped yttrium vanadate nanophosphor. Thin films of such nanophosphor exhibit 80–90% transparency in the visible range. Nanophosphor films convert UV to visible leading to better photon harvesting by solar cells.