What is strontium vanadate?

Strontium vanadate is a transition metal perovskite oxide

There are many Sr-V-O compounds with various properties. Sr2V2O7 single crystal has the following basic properties: the melting point is 1120°C, there are high temperature α phase and low temperature phase, the phase transition point is about 645°C, and the α phase belongs to triclinic crystal The lattice constant is: a=709Å, b=12.99A, c=7.05Å, q=93.8°0=90.88y=99.45 The phase belongs to the monoclinic system, and the lattice constant and density are almost the same as the a phase.

In addition to reducing the cost of application in light-emitting elements and electronic devices, white light-emitting materials can also overcome many problems caused by non-natural color balance. In order to observe this photoluminescence phenomenon, a research team from the University of São Paulo synthesized strontium vanadate (Sr10V6O25, SVO) material at low temperature. This paper discusses how van der Waals forces affect the morphological evolution of semiconductors as a function of orientation, induction, and dispersion interactions. Based on experimental data and theoretical analysis, it is proposed for the first time that the unit of SVO structure is a composite of three twisted [SrOx] (x = 6, 7 and 9) and two twisted [VO4]. Photoluminescence measurements showed efficient broadband emission and conversion of UV excitation to visible light was observed. The emission chromaticity suggests that the structural disorder of the [SrOx] and [VO4] clusters may lead to changes in the CIE emission color.

After the advent of commercial white light, the search for new color-converting phosphors, such as white light-emitting diodes (WLEDs), has been a hot research topic. WLEDs semiconductors have the advantages of high efficiency, low power consumption, good stability, adjustable color, and little harm to the environment, and have an advantage in lighting technology. Therefore, WLEDs devices have a tendency to replace traditional lamps. However, modulation of each phosphor color for reproduction in WLEDs becomes a major challenge due to the low luminous efficiency due to the strong reabsorption of blue light by red and green phosphors. In this way, the single-component white phosphor exhibits luminous efficiency and good color rendering index.

According to the literature, an efficient approach is to use phosphors that convert the UV excitation radiation into broadband emission covering the entire visible light region, as this would reduce the types of phosphors used in LEDs, as well as the cost of production. The vanadate family has been considered as promising LEDs because they exhibit broadband emission covering almost the entire visible light region, high luminous efficiency, and excellent chemical stability. In recent years, the structure of vanadate has been studied due to its luminescent properties. Given the self-activating luminescence properties of VO43-groups, vanadates can efficiently convert UV radiation to visible light.

The luminescence mechanism of vanadium material has been proved to be the charge transfer from the 2p orbital of VO2 to the 3d orbital of V5+. The photoluminescence (PL) of vanadium compounds strongly depends on the degree of deformation of the VO4 tetrahedron, which is influenced by the type and number of cations surrounding the structure, as forbidden by the spin-selection rule in ideal Td symmetry (3T1, 3T2 → 1A1 ) transitions are partially mediated by spin-orbit interactions induced by VO4 tetrahedral distortion. Different photoluminescence was obtained by modifying the cation by substitution network and changing the structural lattice. Strontium vanadate compounds have broad application prospects as luminescent materials, and some structures have been elucidated to be related to luminescent properties, such as Sr2V2O7, Sr3V2O8 and Sr6V2O11.