Enhanced white light luminescence of Ce3+ - activated Y3Al5O12 phosphors powder synthesized via continuous wave (CW) CO2 laser-assisted combustion

摘要

New generation optoelectronic devices such as light emitting diodes (LEDs) promote excellent energy-efficiency and lower consumption of resources that finally yield lower green gas emissions. Ce^{3+-activated Y₃Al₅O₁₂ (YAG:Ce3+) materials have been extensively studied to produce white LEDs (WLEDs) by conversion from blue InGaN LED chips because of its attractive properties, such as high luminescence efficiency and low fabrication cost. The preparation, characterization, and luminescence properties of Y ₃Al₅0₁₂:Ce3+ phosphor powder is presented. In the present work, the phosphors materials were obtained through a novel and fast combustion synthesis technique using continuous wave (CW) CO₂ laser. The whole process took only 1.5 min and yielded chemically homogeneous and small grain size (~70 nm) powder. Pure YAG phase was observed for as prepared powder with spherical particles. However, heat treatment step at 1050°C for 5 h is necessary to enhance luminescence by improving Ce3+ incorporation into the YAG matrix and removing any remaining organic residues from the products. The thermal stability, structure, and morphology of YAG powders were investigated. The luminescence properties of the powders were characterized by determination of their photoluminescence (PL) and electroluminescence (EL) emissions and standard International Commission on Illumination (CIE) 1931 chromaticity diagrams. The highest PL and EL emissions were achieved for the sintered powder, offering cool WLED with a correlated color temperature (CCT) of 6161 K and corresponding color rendering index (CRI) of 67.6.}