Study of the structural, morphological and optical properties of ZnSe doped with Yb3+

Abstract

A wurtzite phase of Zn 1−x Yb x Se (0 ≤ x ≤ 1.8) nanoparticles was synthesized through photo assisted chemical bath deposition. Glancing angle X-ray diffraction disclosed a hexagonal wurtzite crystal structure. The crystallite size (D) of undoped ZnSe was estimated 24.40 nm and then gradually decreased to 4.66 nm, after Yb 3+ doping. Scanning electron microscopy images revealed that with an increase in the Yb 3+ concentration, the thin film morphology transformed from Nano-flakes to spherical particles. The expected elements were confirmed by elemental energy X-ray dispersive analysis. Raman spectroscopy revealed the existence of two distinct optical phonon peaks induced by first- and second-order longitudinal vibration peak located at 257 and 500 cm -1 , respectively. UV–visible spectroscopy elucidated that the absorption spectra showed that the band gap energy for undoped ZnSe thin films can be tuned in the range of 2.76 - 3.12 by varying Yb 3+ concentration. Photoluminescence analysis revealed two emission and shoulder peaks located at 3.19 eV, 2.37 eV and 1.70 eV, which were ascribed to the band-to-band and imperfections of ZnSe, respectively. Chromaticity investigations revealed that the blue emission color was dependent on the concentration of Yb 3+ . The results suggest that Zn 1−x Yb x Se (0 ≤ x ≤ 1.8) is a promising candidate for blue-light emitting phosphor. The data that support the findings of this study are available from the corresponding author upon reasonable request.