Photoluminescence properties and thermal stability of Eu3+-activated La7Ta3W4O30 red-emitting phosphors for near-UV-excited w-LEDs

• 作者: Yu Ren Bin Deng Ting Liang Shuang Shu Junlan Guo Shoucheng Zhao Ruijin Yu
• 来源期刊: 稀土学报（英文版）
• 年，卷（期）: 2021,（8）
• 所属期刊栏目: SPECTROSCOPY,LUMINESCENCE AND PHOSPHORS
• 页码范围: 905-912
• 页数: 8页
• 语种: 英文

摘要

Novel trivalent europium (Eu3+)-activated La7Ta3W4O30∶xEu3+ (x =0.5 mol％-40 mol％) red-emitting phosphors were synthesized by means of a high-temperature solid-state reaction.The structure,morphology,photoluminescence,thermal-stability properties,lifetime,and color-rendering of the pre-pared phosphors were investigated in detail.The La7Ta3W4O30∶Eu3+ phosphors show five emission peaks under near-ultraviolet (n-UV) at 397 nm,and these peaks are ascribed to the transitions of 5D0-7Fj (j =0,1,2,3 and 4) by Eu3+ ions.The optimal doping concentration of Eu3+ is 20 mol％,and the critical distance of the energy transfer between the Eu3+ ions was calculated to be 1.768 nm.The quenching temperature(T0.5) of La7Ta3W4O30:20 mol％Eu3+ is about 440 K.The quantum yield (QY) was measured to be 85.85％.The fabricated white-light-emitting diodes (w-LEDs) possess high color-rendering index (Ra) of 90,and high correlated color temperature (CCT) of 5810 K,respectively.The Commission Internationale de L'Eclairage (CIE) coordinates are (0.311,0.322).Therefore,the prepared phosphor has a promising appli-cation for w-LEDs.