First principle study to investigate color tunable properties in Bi³⁺, Tb³⁺, and Yb³⁺ doped GdVO₄ phosphor

Gadolinium Vanadate (GdVO4) is a luminescent material widely utilized in the production of blue LEDs, owing to its adjustable optical characteristics. By employing density functional theory (DFT) and the EVGGA method, we investigated the impact of doping on the structural, electrical, and optical properties of GdVO4, focusing on Bi, Tb, and Yb doping. Through optimization of the total energy with respect to the unit cell volume, we determined the relaxed structure's electronic properties using the optimized lattice constant. An in-depth analysis of the electronic density of state (DOS), band structure, and linear optical susceptibility revealed a close correlation between the optical dispersion of dielectric susceptibility and the electronic structure, aligning with experimental observations. The color emissions are obtained under single wavelength excitation due to the high overlapping between the VO4 absorption and the pi-pi* electron transition of the ligands. These findings offer valuable insights into the characteristics of GdVO4 and its doped derivatives, facilitating the development of more efficient phosphor materials for application in photoluminescence and pc-LEDs.