Hydrothermal Synthesis of (Lu ₁₋ <i> _x </i> Sc <i> _x </i> )VO ₄ :Bi ³⁺ Micro/Nanocrystals With Tunable Broadband Luminescence for High CRI pc‐WLED

ABSTRACT Without using any organic additive, zircon‐type (space group I 4 1 / amd ) (Lu 1− x Sc x ) 0.99 VO 4 :0.01Bi 3+ ( x = 0−1, 0.1 interval) nano/microcrystals were successfully synthesized via a hydrothermal reaction at 180°C for 24 h. The products were systematically characterized via XRD, FE‐SEM, TEM, elemental mapping, and optical spectroscopy to investigate the effects of Sc 3+ doping on crystal structure, morphology, and luminescent properties. It was found that with the substitution of Lu 3+ by Sc 3+ , the products gradually transformed from LuVO 4 :Bi 3+ nanocrystals into highly anisotropic ScVO 4 :Bi 3+ microrods preferentially growing up along the [001] direction. The peak wavelength of both excitation and emission almost linearly increased with decreasing cell volume, accompanied by band broadening, which was rationalized by considering crystal field splitting energy ( D q), character of the chemical bond (nephelauxetic effect) and metal to metal charge transfer (MMCT) energy. This finely tunable broadband emission (center wavelength 581−639 nm, FWHM &gt;175 nm) enables the materials to supplement multicolor components, presenting potential for application in phosphor‐converted white light‐emitting diode (pc‐WLED) and others.