Photoluminescence of Bi3+ doped in YOF phosphor as an activator

Abstract

Photoluminescence (PL) studies of yttrium oxyfluoride (YOF) doped with bismuth (Bi 3+ ) revealed a broad ultraviolet emission band centered at 31 800 cm −1 that can be applied for silicon solar cells. YOF doped with different Bi 3+ concentrations were synthesized by using the reported pyrolysis technique and annealed at 900 °C. X-ray photoelectron spectroscopy showed two doublet peaks for the Bi 4f region which were attributed to Bi 3+ ions and Bi metal. The PL excitation band was a symmetric broad band centered at 37 500 cm −1 nm and corresponded to the 1 S 0 → 3 P 1 A band with a Stokes shift of 5600 cm −1 . This excitation overlapped with a metal to metal charge transfer band of Bi 3+ . The optimum concentration was 0.4 mol % of Bi 3+ and the quantum yield of this sample was about 60%. • YOF:Bi 3+ revealed a broad UV PL emission band centered at 31 800 cm −1 . • The quantum yield obtained was 60%. • Samples were synthesized by using the pyrolysis technique. • XPS showed Bi 3+ ions and Bi metal.