透明导电ITO欧姆接触的AlGaInP薄膜发光二极管

提出了一种透明导电氧化铟锡(ITO)欧姆接触的AlGaInP薄膜发光二极管(LED)的结构和制作工艺.在这个结构里,ITO还作为窗口层材料,增强电流扩展,并应用了高反射率的金属作为反光镜.用Au-Sn合金(Au∶Sn＝8∶2,重量比)作为焊料,把带有金属反光镜的AlGaInP LED(RS-LED)外延片倒装键合到GaAs基板上,并去掉外延GaAs衬底,把被GaAs衬底吸收的光反射出去.与常规AlGaInP吸收衬底LEDs(AS-LED)和带有分布布拉格反光镜(DBR)的AlGaInP吸收衬底LEDs(DBR-AS-LED)电、光特性的比较,用透明导电ITO做欧姆接触的AlGaInP薄膜RS-LED结构能极大提高光输出功率和发光强度.正向电流20 mA时,RS-LED的光输出功率分别是AS-LED和DBR-AS-LED的2.4倍和1.7倍;RS-LED 20 mA下峰值波长624 nm的轴向光强达到了179.6 mcd,分别是AS-LED 20 mA下峰值波长627 nm和DBR-AS-LED 20 mA下峰值波长623 nm轴向光强的2.2倍和1.3倍.

AlGaInP Thin-Film Light Emitting Diodes with Transparent Conducting Indium Tin Oxide p-type Ohmic Contacts

A high efficient AlGaInP thin-film light emitting diode(LED) with transparent conducting indium tin oxide(ITO) p-type ohmic contacts and with a high reflectivity metal reflector structure was proposed.ITO layers are also used as window material and spreading layers of current on AlGaInP LED.The AlGaInP LED epitaxial layers with metal reflector is inverted to bond to the GaAs submount by using 80 Au-20 Sn(wt%) alloy as a solder (RS-LED).The optical and electrical characteristics of the new structure LED(RS-LED) are presented and compared with conventional AlGaInP absorbing substrates AS-LED and AS-LED with DBR Great improvements in output power and luminous intensity were observed.It is shown that the output power from the RS-LED at forward current 20 mA is 2.4 and 1.7 times higher than that of AS-LED and DBR-AS-LED respectively.179.6 mcd luminous intensity from the RS-LED (@20 mA,peak wavelength 624 nm) could be obtained under 20 mA injection,which is 2.15 and 1.28 times higher luminous intensity than that of AS-LED (@20 mA,peak wavelength 627 nm) and DBR-AS-LED (@20 mA,peak wavelength 623 nm),respectively.