A research on full-color LED using UV light emitting devices

利用紫外发光器件的全彩LED的研究

• 批准号: 07555102
• 负责人: SAKAI Shiro
• 金额: $ 4.86万
• 依托单位: The University of Tokushima
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07555102/
• 关键词: GaN; InGaN; Bulk GaN; MOCVD; LED; Semiconductor lasers; Homoepitaxy; Dislocation; ワイドギャップ半導体; 厚膜; 昇華法; 青色発光素子

Although a blue-to UV nitride light emitting devices are realized, many problems still remain unsolved. The LED is most commonly fabricated by growing InGaN/AlGaN double-heterostructure on sapphire substrate by MOCVD technique. However, the growth critically depends on the substrate annealing prior to the growth and the deposition conditions of the low-temperature buffer layrs making the growth extremely difficult. In addition, the misfit dislocation was recently shown to work as a non-radiative recombination center. Therefore, the elimination of the dislocation can substantially improve LED efficiency and lower the threshold current of the lasers. In this research, the growth of bulk GaN and a homoepitaxy by MOCVD were tried and investigated in detail. The following topics were investigated.1.Growth of thick GaN and bulk GaN by sublimation method : A GaN with a thickness of several tens of mum to several hundred of mum on sapphire and a bulk GaN with the size of several hundreds of mum to several mm were obtained. A technique to grow bulk GaN in the selective area on the substrate was developed, and the device processing of the bulk GaN became possible.2.Growth of InGaN on sapphire : GaN and InGaN films were grown on sapphire by MOCVD,and the layrs were characterized. Especially, the formation mechanism of the inhomogeneity in InGaN was investigated in detail.3.Homoepitaxial growth : GaN and GaN/InGaN double-heterostructure were grown on bulk GaN by MOCVD and the grown layrs were characterized. It wasfound that the growth mode on the bulk substrate was very different of that on the sapphire substrate.Above research results provided the basis for fabricating super-high-efficiency-LED and nitride lasers on a bulk GaN substrate.

虽然实现了蓝光至UV氮化物发光器件，但仍有许多问题未解决。LED最常用的制造方法是通过MOCVD技术在蓝宝石衬底上生长InGaN/AlGaN双异质结构。然而，生长关键地取决于生长之前的衬底退火和低温缓冲层的沉积条件，使得生长极其困难。此外，最近的失配位错被证明是一个非辐射复合中心。因此，位错的消除可以显著提高LED效率并降低激光器的阈值电流。在本研究中，我们尝试以MOCVD法生长氮化镓体材料及同质磊晶。主要研究内容如下：1.升华法生长厚GaN和GaN体材料：在蓝宝石衬底上生长了厚度为几十到几百μ m的GaN和尺寸为几百到几mm的GaN体材料。发展了一种在衬底上选择性区域生长GaN体材料的技术，使GaN体材料的器件加工成为可能。2.蓝宝石衬底上InGaN的生长：采用MOCVD方法在蓝宝石衬底上生长GaN和InGaN薄膜，并对其进行了表征。3.同质外延生长：采用MOCVD方法在体GaN上生长了GaN和GaN/InGaN双异质结构，并对生长层进行了表征。研究结果表明，在体GaN衬底上的生长模式与在蓝宝石衬底上的生长模式有很大不同，为在体GaN衬底上制备超高效LED和氮化物激光器奠定了基础.

项目成果

S.Kurai, Y.Naoi, T.Abe, S.Ohmi and S.Sakai: "Photopumped Stimulated Emission from Homoepitaxial GaN Grown on Bulk GaN Prepared by Sublimation Method" Jpn.J.Appl.Phys.Vol.35, No.1B. L77-79 (1996)

S.Kurai、Y.Naoi、T.Abe、S.Ohmi 和 S.Sakai：“在升华法制备的块状 GaN 上生长的同质外延 GaN 的光泵受激发射”Jpn.J.Appl.Phys.Vol.35，第 35 期。

S.Kurai,K.Nishino and S.Sakai: "Nucleation Control in the Growth of Bulk Gan by Sublimation method" Jpn.J.Appl.Phys. (in press). (1996)

S.Kurai、K.Nishino 和 S.Sakai：“升华法对块状甘生长的成核控制” Jpn.J.Appl.Phys。

T.Yang, S.Nakajima and S.Sakai: "Electronic Structures of Wurtzite GaN,InN and their Alloy Ga_<1-X>In_XN Calculated by the Tight-Binding Method" Jpn.J.Appl.Phys.Vol.34, No.11. 5912-5921 (1995)

T.Yang、S.Nakajima 和 S.Sakai：“用紧束缚法计算的纤锌矿 GaN、InN 及其合金 Ga_<1-X>In_XN 的电子结构” Jpn.J.Appl.Phys.Vol.34，

Nakajima, T.Yang and S.Sakai: "Electronic Structure of Ga_<l-x>ln_xN by the Tight-Binding Method with Nearest-Neighbor s, p and d and Second-Neighbor s and p Interactions" International Conference on Silicon Carbide and Rerated Materials-1995, Institute o

Nakajima、T.Yang 和 S.Sakai：“Electronic Structure of Ga_<l-x>ln_xN by the Tight-Binding Method with Nearest-Neighbor s, p and d and Second-Neighbor s and p Interactions” 碳化硅国际会议及重新评级

H.Sato, M.R.Sarkar, Y.Naoi and S.Sakai: "XPS Measurement of Valence Band Discontinuity at GaP/GaN Heterointerfaces" Solid State Electronics. (in press).

H.Sato、M.R.Sarkar、Y.Naoi 和 S.Sakai：“GaP/GaN 异质界面价带不连续性的 XPS 测量”固态电子学。