Solution combustion synthesis of Dy3+doped La2O3 nanoparticles: An investigation of their structural, optical and photoluminescence characteristics

Abstract

The impact of the varying Dy3+ (1–9 mol %) rare earth ion concentration on the structural and luminous characteristics of La2O3 phosphors was studied via solution combustion synthesis. Structure formation, photoluminescence (PL) effectiveness, optical properties, and energy transfer mechanisms were examined in detail. All the synthesised samples exhibits hexagonal structure, which is supported by X-ray diffraction patterns (space group: P-3 mL (164)). Scanning electron microscope analysis shows irregular particle size and shapes of the synthesised materials. The presence of prominent and dominant Dy3+ ion peaks in the excitation spectrum of the ideal sample material, correlate to the Dy3+ ion's absorption peaks, supports the existence of considerable energy transfer among La3+ and Dy3+ ions. The PL emission wavelengths at 486 and 570 nm assigned to the Dy3+ ions transitions 4F9/2 → 6H15/2 and 4F9/2 → 6H13/2 respectively owing to the charge-transfer between La3+ and Dy3+ ions. PL emission intensity increases up to 3 mol% and afterwards it starts to decrease due to concentration quenching caused by non-radiative interactions. Photometric properties were investigated to check the possible utilization of La2O3:Dy3+ phosphor in white light emitting diodes application with CIE (x- 0.3468, y- 0.3986), CCT (0.1957, 0.5060), and colour purity (23.8 %). Aforementioned findings suggest that the synthesized phosphor is a viable option for making w-LEDs using NUV chips serving as the source of excitation.