Er3+ activated LaAlO3 perovskite phosphor: Crystal structure and down conversion photoluminescent behaviour for optoelectronic devices

Abstract

• Trivalent Erbium activated LaAlO 3 perovskite materials were synthesized effectively through urea assisted gel-combustion method. • Rietveld refinement technique was utilized to confirm the structure of prepared materials and estimate various structural parameters. • G. Blasse’s theory was applied to understand the quenching effect of concentration. • The suitable color parameters of synthesized materials make them promising agent for optoelectronic devices. A series of green light emissive La 1-x AlO 3 :xEr 3+ (x = 0.01 to 0.08) nanophosphors were effectively synthesized via reliable, ecofriendly and low temperature based urea assisted gel-combustion process. The diffraction patterns and refinement data have revealed that the synthesized material is crystalline in nature with single phase cubic crystal structure having space group Pm3̅m (2 2 1). Moreover, the crystallite sizes were calculated by Debye-Scherrer’s formula (19–32 nm) and Williamson-Hall method (40–70 nm). Transmission electron microcopy image has affirmed the smooth morphology, uniform distribution of particles (40–70 nm) with some agglomeration. The examination of chemical bonding with vibrational characteristics was carried out by Fourier transform infrared (FTIR) spectroscopy. Elemental purity was proven by EDX analysis of the synthesized materials. The photoluminescence emission spectrum of the present phosphors was recorded at excitation wavelength of 376 nm and most intense peak detected on 548 nm with 4 S 3/2 → 4 I 15/2 which is responsible for the intense green color. In the luminescence intensity, a regular increasing fashion was observed with the concentration of Er 3+ ion upto 0.05 (called critical concentration) and then continuously decreased because of concentration quenching effect. Enhanced CIE parameters like chroma coordinates (0.307, 0.587), CCT value (5952.92 K) and color purity (94.41%) validate the potentiality of the synthesized phosphors in optoelectronic applications and other different lighting fields.