Mechanoluminescence & Thermoluminescence of SrAL2O4: EU Nano-Phosphors

Abstract

Eu doped strontium Aluminate phosphors were synthesized by combustion method using urea as a reducer at initiating temperature of 600 o C. We have investigated the Fracto-Mechanoluminescence (ML) and Thermoluminescence (TL) of SrAl 2 O 4 : Eu. Two peaks have been found in time Vs ML intensity plot. The peak of ML intensity Vs time curve increases with increasing velocity of the piston. The total ML intensity (area below the curve) also increases with impact velocity and attains saturation at higher value of the impact velocity. We have also investigated that the ML intensity is completely recovered by irradiation with ultraviolet light. The TL intensity was recorded for different exposure time with UV light and it was observed that TL intensity is maximum for 15 minute exposure time. We have calculated the trap depth by different methods.

Recent progress in understanding the persistent luminescence in SrAl2O4:Eu,Dy

“…At this point, the mechanism where the electrons are considered to be the main charge carriers has become the predominant one and one of the reasons to assert this is the mathematical calculations of the band structure and the rare earth levels in the host band structure. J. Holsa et al, Nazarov et al, Zhai et al and others have worked on the ab initio calculations of the structural and electronic properties of the material [15,24,[63][64][65][66][67][68][69][70]. Several things have been confirmed by these calcula-tions.…”

Advanced Thermoluminescence Spectroscopy as a Research Tool for Semiconductor and Photonic Materials: A Review and Perspective

“…[35,36] TL or TSL has been widely applied for measuring deep and relatively shallow traps in optical and photonic materials [37,38] and has been quite useful for optical studies of single crystals, films, phosphors, and transparent ceramics for lasers, scintillators, and solid-state lighting applications and more. [9,[39][40][41][42][43][44][45][46][47][48][49][50][51][52][53] However, its applications in semiconductors has not been realized until recently [5,8,54] and are still very limited. The goal of this article is to explain the basics of TL, inform the reader about its capability as a great tool for measuring the energy levels of donors and acceptors in semiconductors, and bring the attention to the development of cryogenic thermally stimulated photoemission spectroscopy (C-TSPS) [55] which extends TL or thermally stimulated emission measurements to cover the entire range of shallow and deep levels in bandgap materials.…”