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Mechanoluminescence (ML)Photoluminescence Thermolumenescence Impact velocity a b s t r a c tThe present paper reports the synthesis and characterization, photoluminescence thermoluminescence and mechanoluminescence studies of Ce 3þ doped SrZrO 3 phosphors. The effects of variable concentration of Cerium on meachanoluminescence (ML) and photoluminescence behavior were studied. The samples were prepared by combustion a synthesis technique which is suitable for less time taking techniques also for large scale production for phosphors. The starting material used for sample preparation are Sr(NO 3 ) 3 , Zr(NO 3 ) 3 XH 2 O and Ce(NO 3 ) 3 6H 2 O and urea used as a fuel. The prepared sample was characterized by X-ray diffraction technique (XRD) with variable concentration of Ce (0.05 e0.5 mol%). There is no any phase change found with increase the concentration of Ce. Sample shows orthorhombic structure and the particle size calculated by Scherer's formula. The surface morphology of prepared phosphor was determined by field emission gun scanning electron microscopy (FEGSEM) technique. Mechanoluminescence studies on SrZrO 3 phosphors doped with Ce and underwent an impulsive deformation with an impact of a piston for Mechanoluminescence (ML) investigations. Temporal characteristics in order to investigate about the luminescence centre responsible for ML peak, increasing impact velocity causes more number of electrons will be ionized to reach to the conduction band so there will be more number of electrons available to be recombined at recombination or luminescence centre. In photoluminescence study PL emission spectra show the isolated peak position observed at 388 nm near UV region of spectrum due to 5de4f transition of Ce 3þ ion.Thermoluminescence study shows doping of Ce 3þ ions reduced the TL intensity TL glow curve shows the high fading and less stability when it doped with cerium. The activation energy high for the doped SrZrO 3 phosphor means that the trapped electron is highly trapped in trap level. The present study gives the advance application for fracture sensor, damage sensor including the biological sensor and development of solid state lighting.

Currently there is a great interest in II–VI semiconductor nanoparticles, particularly organically capped soluble particles of cadmium or zinc sulphide and selenide, for their ready to use application in devices. For electroluminescence (EL) devices, it is expected to cover a broad spectrum and to tune various specific colours by preparing Cd1-xZnx Se instead of CdSe and ZnSe. Ternary alloys have composition dependent properties; therefore Cd1-xZnxSe has attracted much attention in the fields of luminescence and optoelectronic devices. It has wide optical band-gap and good stability with respect to environment. In this study, Cd1-xZnxSenanoparticles have been synthesized by using starch as a capping agent through a chemical synthesis route at room temperature. Samples have been prepared varying composition factor ‘x’ in ternary alloy Cd1-xZnxSe. Cubic structure of all has been confirmed by XRD. Crystallite size calculated from XRD was found in the range of 3-5 nm and it was observed that size reduces on increasing Zn content in ternary compound. Optical absorption spectra showed the blue shift in absorption edge with increasing Zn content. Band gap has been obtained by absorption studies and increase in band gap observed on increasing Zn content in the compound. Electroluminescence studies reveal that lower threshold voltage is required for samples with lower ‘x’ value. The Brightness increases on increasing the voltage above threshold voltage and the variation pattern is almost exponential for all samples. The voltage-current curve represents ohmic nature of the EL cell. Impedance was found to increase on increasing ‘x’ value. The increase in EL intensity is faster for higher frequency. EL spectra revealed that light emission is in violet-green region corresponding to band gap for both Cd0.75 Zn 0.25Se and Cd0.5 Zn 0.5Se, with a slight blue shift on increasing Zn content. A ternary system Cd1–xZnxSe, may be engineered better for application purpose by suitably choosing the composition parameter ‘x’.Contents of Paper