SYNTHESIS AND PHOTOLUMINESCENCE PROPERTIES OF SM3+DOPED KMGPO4 PHOSPHORS FOR WHITE LIGHT EMITTING DIODES

Abstract

Sm3+- doped KMgPO4 was prepared by high-temperature solid-state reaction having exceptionally bright and stable photoluminescence in the orange (602 nm) region of the electromagnetic spectrum. The X-ray powder diffraction, photoluminescence (PL) emission, and excitation spectra were thoroughly measured. The PL spectra of prepared KMgPO4 phosphor showed characteristic Orange emission when excited by 402 nm under UV excitation. The highest emission intensity was found for KMgPO4:xSm3+ with a composition of x=0.0075 Sm3+ ions and this phosphor used for remaining studies. The photoluminescence at room temperature shows broad orange 5d-4f emission bands are peaked at 602 nm and only two weak Sm3+ emission band is observed at 565 nm and 652 nm respectively. The phosphor was found to be superior in terms of integrated PL intensity, degradation resistant and markedly superior properties as compared to its counterparts. The objective of this dissertation is to synthesize the KMgPO4 phosphor and study the photoluminescence properties of the KMgPO4 phosphor doped with Sm3+ ions. These results can be used in the white LED for improved performance and stability. Further different characterization techniques used in the study of KMgPO4 such as photoluminescence, SEM, XRD and FTIR. The thesis has been divided into the various chapters. In chapter 1, Introduction for the research have been explained in brief. In chapter 2, different instrumentation used in the experimental work and synthesis of KMgPO4 phosphor have been discussed. In chapter 3, the characterization of the prepared samples have been explained. The conclusion and future iv work have been explained in chapter 4. Finally, all the references used in the research have been mentioned in the last.