光提取效率的提高对GaN基蓝光LED的广泛应用有重要的影响.计算了以Ni/Au基金属化方法形成的p型GaN电极的折射率,通过分析电极层中的能流传输情况在电极上设计高折射率的耦合层来减少电极层对光的吸收以及提高光的透射,耦合层通过采用圆台结构来减少光在空气/耦合层界面上的全反射以提高GaN基蓝光LED的光提取效率.应用传输矩阵法计算的结果表明,光学厚度为π/2,折射率为2.02的ITO耦合层能使450 nm的蓝光在膜系上的透射率提高到75%.
参考文献
| [1] | Pearton S J,Zolper J C,et al.GaN:Processing,defects,and devices[J].J.Appl.Phys.,1999,86(1):1-78. |
| [2] | Jain S C,Willander M,Narayan J,et al.Ⅲ-nitrides:Growth,characterization,and properties[J].J.Appl.Phys.,2000,87(3):965-1006. |
| [3] | Liu Jianbin,Li Peixian,Hao Yue.Research and development of high brightness GaN-based blue LED and white LED[J].Chinese Journal of Quantum Electronics (量子电子学报),2005,22(5):673-679 (in Chinese). |
| [4] | Ho J K,Jong Charng-Shyang,Chiu Chien C,et al.Low-resistance ohmic contacts to p-type GaN[J].Appl.Phys.Lett.,1999,74 (9):1275-1277. |
| [5] | Li Chien Chen,Fu Rong Chen,Ji Jung Kai,et al.Microstructural investigation of oxidized Ni/Au ohmic contact to p-type GaN[J].J.Appl.Phys.,1999,86 (7):3826-3832. |
| [6] | Wang Peihong,Cai Qi,Wang Lei,et al.Application of effective medium theories to Ag2MgF2 granular film[J].Vacuum Science and Technology (真空科学与技术),2003,23(6):413-416 (in Chinese). |
| [7] | Shulz L G.The optical constants of silver,gold,copper and aluminum.1.the absorption coefficient and 2.the index of refraction n[J].J.Opt.Soc.Am.,1954,44 (5):357-368. |
| [8] | Analysis and Testing Center of Zhengzhou University.Refraction indices of common partices,http://zzu.hnyqw.com/upload/doc/zheshelu.pdf. |
| [9] | Lin Y C,Chang S J,Su Y K,et al.Nitride-based light-emitting diodes with Ni/ITO p-type ohmic contacts[J].IEEE Photonic Technology Lett.,2002,14(12):1668-1670. |
| [10] | Kuo C H,Chang S J,Su Y K,et al.Nitride-based near-ultraviolet LEDs with an ITO transparent contact[J].Materials Science and Engineering,2004,B(106):69-72. |
| [11] | Laux S,Kaiser N,Zoler A,et al.Room-temperature deposition of indium tin oxide thin films with plasma ion-assisted evaporation[J].Thin Solid Films,1998,335:1-5. |
| [12] | Lin C H,Hibbard D L,Au A,et al.Low resistance optically transparent contacts to p-type GaN using oxidized Ni/Au and ITO for LED application[J].Mat.Res.Soc.Symp.,2001,639:G4.8.1-G4.8.6. |
| [13] | Jung Sung-Pyo,Ullery Denise,Lin Chien-Hung,et al.High-performance GaN-based light-emitting diode using high-transparency Ni/Au/Al-doped ZnO composite contacts[J].Appl.Phys.Lett.,2005,87(181107):1-3. |
| [14] | Wierer J J,Steigerwald D A,Krames M R,et al.High-power A1GaInN flip-chip light-emitting diodes[J].Appl.Phys.Lett.,2001,78 (22):3379-3381. |
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