A novel AlGalnP thin-film light emitting diode with omni directional reflector

作者：Zhang Jian Ming^*; Zou De Shu; Liu Si Nan; Xu Chen; Shen Guang Di

来源：Acta Physica Sinica, 2007, 56(5): 2905-2909.

• AlGaInP
• thin-film LED
• omni directional reflector
• luminous intensity

A novel AlGaInP thin-film light emitting diode (LED) with omni directional reflector structure was proposed, the corresponding fabrication process was developed. This reflector is realized by the combination of a low-refractive-index dielectric layer and a high reflectivity metal layer. The AlGaInP LED layers with dielectric-metal reflector is inverledly bonded to the GaAs submount by using 80Au-20Sn (wt%) alloy as a solder (Reflector-Submount, RS-LED), and then GaAs substrate is removed. The light that would otherwise be absorbed by the GaAs substrate is reflected by the high reflectivity dielectric-metal reflector. The optical and electrical characteristics of the RS-LED are presented and compared with the conventional AlGaInP absorbing substrate (AS) LED and AlGaInP absorbing substrate LED with distributed Bragg reflectors (DBR). A great improvement in the brightness and efficiency is observed. It is shown that the light output and lumen efficiency from the RS-LED at forward current 20 mA exceed those of AS-LED by about a factor of 2.2 and 1.2, respectively, and similar to 2 x the light output of AS-LED (DBR) and similar to 1.5 x the lumen efficiency of AS-LED (DBR) were achieved. 194.3 mcd luminous intensity from the RS-LED (at 20 mA, peak wavelength 627 nm) could be obtained under 20 mA injection, which is 2.8 and 1.6 times higher in luminous intensity than the AS-LED (at 20 mA, peak wavelength 624 nm) and AS-LED(DBR) (at 20 mA, peak wavelength 623 nm), respectively.

• 出版日期2007-5
• 单位北京光电技术研究所; 北京工业大学