Lysine assisted hydrothermal synthesis and formation process of MoO3:Sm3+ phosphors with hierarchical structures and its electron trapping luminescence properties

Abstract

We report the synthesis of Sm3+ doped MoO3 nanostructures (NSs) effectively by hydrothermal route using lysine as surfactant. The hexagonal and orthorhombic phases were confirmed by means of Powder X-ray diffraction (PXRD) results. The effect of hydrothermal reactions, such as reaction temperature, surfactant concentration, pH value on the morphology was studied in detail by utilizing scanning electron microscopy (SEM) results. Optical properties of the Sm3+ (1–9 mol %) doped MoO3 were studied by means of diffuse reflectance spectroscopy (DRS). The 4f-4f emission bands of Sm3+ ions were observed at 563, 610, 647 and 698 nm attributed to 4G5/2–6HJ (J = 5/2, 7/2, 9/2, 11/2) of Sm3+ respectively under 409 nm excitation. Judd–Ofelt theory was utilized to calculate the, transition probabilities (AT), radiative lifetime (τrad), branching ratio (β), and asymmetric ratio (A21) by using the intensity parameters. The average quantum efficiency and color purity values of the prepared samples were found to be ∼79.61% and 97% respectively. The CIE color coordinates confirmed that the phosphor emits orange-red light, which were quite useful for the fabrication of white light emitting diodes.