Eu3+ activated terbium oxalate nanocrystals: A novel luminescent material with delayed concentration quenching and tunable multicolour emission

Abstract Tunable multicolour emitting Eu3+ activated Terbium oxalate nanophosphors synthesised by simple microwave assisted co-precipitation method is bring forth. The powder X-ray diffraction analysis confirmed the crystal system of synthesised nanophosphors as monoclinic system with space group P21/c. The photoluminescence properties and energy transfer from Tb3+ to Eu3+ ions were analyzed systematically. The luminescence emission spectra and decay curves were analyzed based on the relative fraction of Tb3+/Eu3+ ions in oxalate matrix. Evidences for efficient energy transfer and the subsequent multicolour emission from green to red in the oxalate matrix were established by photoluminescence excitation, emission and decay kinetics. The present investigation revealed a dipole-dipole interaction mechanism for energy transfer between Tb3+ and Eu3+ with an energy transfer efficiency of 90%. The quenching free nature of oxalate matrix provided by the structure specificity ensures higher luminescence performance and makes it a suitable candidate for optical applications.