Upconversion luminescence and time decay study of Yb–Er-doped BaWO4 nanophosphor

Rare earth-doped phosphor materials have always remained in focus for excellent luminescence properties. Herein we have synthesized Yb3+ and Er3+-doped BaWO4 nanophosphor via facile hydrothermal method with red and green region emissions by 980 nm excitation. Red and green region emissions were observed due to 4F9/2 → 4I15/2 and 2H11/2/4S3/2 → 4I15/2 transitions, respectively, of Er3+, where Yb3+ acts as a sensitizer. The sample characterization was done using X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Transmission Electron Microscopy (TEM), and X-ray Photoelectron Spectroscopy (XPS) techniques. The consequences of different concentrations of activator ion (Er3+) in BaWO4: Yb3+, Er3+ were studied from luminescence perspective in detail. The intensity of overall emission varied with altering the power of excitation that influences the photon transfer pathways. It was found that two-photon processes control both red and green emissions in the upconversion process. Decay behavior for both the emission was investigated. Thus, the tunable photoluminescence property suggests its potential in optoelectronic applications.