用电子束蒸发技术制备了 GaAlAs/GaAs 和 InGaAsP/InP 发光管的减反射膜。从不同的 LED 和膜厚所获得的结果表明:0.85μm 或0.9μm GaAlAs/GaAsLED 端面上的单层(λ/4)Al_2O_3 AR 膜,能使之明显地增加输出光功率,其输出功率在50mA 和100...用电子束蒸发技术制备了 GaAlAs/GaAs 和 InGaAsP/InP 发光管的减反射膜。从不同的 LED 和膜厚所获得的结果表明:0.85μm 或0.9μm GaAlAs/GaAsLED 端面上的单层(λ/4)Al_2O_3 AR 膜,能使之明显地增加输出光功率,其输出功率在50mA 和100mA 电流下通常可以增加25%～35%,最大达50%。但1.3μm 的InGaAsP/InP LED 上,单层的 ZrO_2 AR 膜比 Al_2O_3 AR 膜好。最后讨论了与输出功率和膜厚有关的问题。展开更多
The effect of patterned sapphire substrate（PSS） on the top-surface（P-Ga N-surface） and the bottomsurface（sapphire-surface） of the light output power（LOP） of Ga N-based LEDs was investigated, in order to study ...The effect of patterned sapphire substrate（PSS） on the top-surface（P-Ga N-surface） and the bottomsurface（sapphire-surface） of the light output power（LOP） of Ga N-based LEDs was investigated, in order to study the changes in reflection and transmission of the Ga N-sapphire interface. Experimental research and computer simulations were combined to reveal a great enhancement in LOP from either the top or bottom surface of Ga N-based LEDs, which are prepared on patterned sapphire substrates（PSS-LEDs）. Furthermore, the results were compared to those of the conventional LEDs prepared on the planar sapphire substrates（CSS-LEDs）. A detailed theoretical analysis was also presented to further support the explanation for the increase in both the effective reflection and transmission of PSS-Ga N interface layers and to explain the causes of increased LOP values. Moreover, the bottom-surface of the PSS-LED chip shows slightly increased light output performance when compared to that of the top-surface. Therefore, the light extraction efficiency（LEE） can be further enhanced by integrating the method of PSS and flip-chip structure design.展开更多
In order to promote the light output powers of GaN-based light emitting diodes (LEDs), two kinds of novel corrosive liquidshave been developed in this paper to roughen the surface of the indium tin oxide (ITO) current...In order to promote the light output powers of GaN-based light emitting diodes (LEDs), two kinds of novel corrosive liquidshave been developed in this paper to roughen the surface of the indium tin oxide (ITO) current spreading layer of LEDs. As aresult, the textured transparent ITO layer greatly enhanced the external quantum efficiency of the LEDs. Provided that a wafersample was dipped in a kind of corrosive liquid developed by us for only about 60 s, the light output powers of the LEDs canbe promoted by 24.7%, compared with conventional GaN-based LEDs. It is obvious that the presented method is simple, rapidand cost-effective.展开更多
文摘用电子束蒸发技术制备了 GaAlAs/GaAs 和 InGaAsP/InP 发光管的减反射膜。从不同的 LED 和膜厚所获得的结果表明:0.85μm 或0.9μm GaAlAs/GaAsLED 端面上的单层(λ/4)Al_2O_3 AR 膜,能使之明显地增加输出光功率,其输出功率在50mA 和100mA 电流下通常可以增加25%～35%,最大达50%。但1.3μm 的InGaAsP/InP LED 上,单层的 ZrO_2 AR 膜比 Al_2O_3 AR 膜好。最后讨论了与输出功率和膜厚有关的问题。
基金Project supported by the National High Technology Program of China (No.Y48A040000)
文摘The effect of patterned sapphire substrate（PSS） on the top-surface（P-Ga N-surface） and the bottomsurface（sapphire-surface） of the light output power（LOP） of Ga N-based LEDs was investigated, in order to study the changes in reflection and transmission of the Ga N-sapphire interface. Experimental research and computer simulations were combined to reveal a great enhancement in LOP from either the top or bottom surface of Ga N-based LEDs, which are prepared on patterned sapphire substrates（PSS-LEDs）. Furthermore, the results were compared to those of the conventional LEDs prepared on the planar sapphire substrates（CSS-LEDs）. A detailed theoretical analysis was also presented to further support the explanation for the increase in both the effective reflection and transmission of PSS-Ga N interface layers and to explain the causes of increased LOP values. Moreover, the bottom-surface of the PSS-LED chip shows slightly increased light output performance when compared to that of the top-surface. Therefore, the light extraction efficiency（LEE） can be further enhanced by integrating the method of PSS and flip-chip structure design.
基金supported by the Natural Science Foundation of Guangdong Province, China (Grant Nos. 8251063101000007, 10151063101000009 and 9451063101002082)the Scientific & Technological Plan of Guangdong Province (Grant Nos. 2008B010200004, 2010B010600030 and 2009B011100003)+2 种基金the National Natural Science Foundation of China(Grant Nos. 61078046 and 10904042)the Key Project of Chinese Ministryof Education (Grant No. 210157)the Scientific & Technological Project of Education Department of Hubei Province (Grant No. D20101104)
文摘In order to promote the light output powers of GaN-based light emitting diodes (LEDs), two kinds of novel corrosive liquidshave been developed in this paper to roughen the surface of the indium tin oxide (ITO) current spreading layer of LEDs. As aresult, the textured transparent ITO layer greatly enhanced the external quantum efficiency of the LEDs. Provided that a wafersample was dipped in a kind of corrosive liquid developed by us for only about 60 s, the light output powers of the LEDs canbe promoted by 24.7%, compared with conventional GaN-based LEDs. It is obvious that the presented method is simple, rapidand cost-effective.
