Photoluminescence and thermoluminescence kinetic features of Eu3+ doped Sr2YVO6 double perovskite phosphor

Abstract

Nowadays, remarkable attention has been paid to exploring the materials containing rare earth elements because of their practical technological applications. Rare earth doped phosphors with excellent luminescent properties were actively researched and used in solid-state lighting devices, color display, X-ray imaging, and radiation dosimetry [[1], [2], [3]]. The doping of rare earth ions in the inorganic material give rise to luminescence properties. Transitions that occur due to the 4f state of rare earth ions are responsible for the emission of visible light. Because of their abundant color emission, rare earth ions with abundant energy levels following the 4f-4f and 5d-4f transitions play an important role in modern lighting and display devices [[4], [5], [6]]. Furthermore, rare earth ions are frequently used as activators in the host matrix, particularly Eu3+, due to their effective excitations in the UV and blue spectral regions. In recent years, phosphor-converted light emitting diodes (pc-LEDs) have gained popularity as a next-generation lighting source. Phosphor-converted LED can replace traditional fluorescence and incandescent lamps due to their excellent benefits such as low power consumption, high luminescence efficiency, and high durability. Currently, commercially available white light emitting diodes (WLEDs) consist of an InGaN chip fabricated with YAG:Ce3+ garnet [[7], [8], [9], [10]]. This WLED combination has a high correlated color temperature and a low color rendering index due to a deficient red component [11,12]. To overcome this disadvantage, an efficient red emitting phosphor must be developed. Because of its 5D0-7FJ (J = 1,2,3,4) electronic transition, trivalent rare earth ion Eu3+ exhibits excellent red spectral emission. Many phosphors doped with Eu3+ have been reported as red emitting phosphors in the literature, including Sr2GdTaO6 [13], La2LiSbO6 [14], YBO3 [15], Sr2CeO4 [16], Ca2Al2SiO7 [17]. In present study, the luminescence properties of Eu3+ doped double perovskite Sr2YVO6 have been investigated. From the literature survey, it is found that perovskites are good candidate to investigate for luminescence properties by doping rare earths due to their high thermal and chemical stability. The general formula for double perovskite A2BB'O6 has a very broad chemical composition range and can be a very good host lattice for luminescence studies. Several Eu3+ doped double perovskites have been investigated previously for their good red emission display, including Ba2YZrO6 [18], Ca2GdTaO6 [19], La2ZnTiO6 [20], Ca2ZnWO6 [21], Ca2YTaO6 [22]. In addition, various Eu3+ doped phosphors were studied for their personal, medicinal, environmental, and radiation dosimetry by considering the thermoluminescence dosimetry (TLD) application. The thermoluminescence investigation of phosphor provides information about the electron traps in materials. The thermoluminescence parameters, including dose rate dependence and dose response, should be evaluated to govern the dosimetry feature of the material. According to a literature review, several double perovskites doped with rare earths were investigated for their excellent PL display but not for their TL studies or TLD investigation. Our luminescence research group has previously worked on luminescent phosphors with excellent TLD applicability [23,24]. Therefore, we were motivated to explore the perovskites for their thermoluminescence properties and TLD applications. Glow curve analysis was used to determine trapping parameters such as activation energy/trap depth, order of kinetics, and frequency factor. To analyse the TL glow curves and evaluate the trapping parameters, Chen's peak shape method and computerised glow curve deconvolution method were used. To the best of our knowledge, the luminescence properties of Sr2YVO6:Eu3+ phosphor have not been reported yet. As a result, a series of Eu3+ activated Sr2YVO6 phosphors with varying Eu3+ dopant concentrations were synthesized using the combustion method, and their luminescence properties were investigated.