标题: 半极化面氮化铟镓/氮化镓全彩奈米金字塔发光二极体之制作及特性研究
Fabrication and Investigation of Full Color Emission Semipolar InGaN/GaN Nanopyramid Light Emitting Diode
作者: 苏国斌
Sou, Kuok-Pan
张俊彦
许根玉
Chang, Chun-Yen
Hsu, Ken-Yuh
光电工程学系
关键字: 氮化镓;奈米结构;金字塔;半极化面;全彩;发光二极体;GaN;NanoStructure;Pyramid;Semi-Polar;Full Color;Light Emitting Diodes
公开日期: 2012
摘要: 本篇论文中,我们介绍如何在极化面氮化镓奈米柱基板上,使用选区成长技术成长高铟含量的半极性面{10-11}氮化铟镓/氮化镓多量子阱结构。
我们使用电浆辅助化学气相沉积(Plasma Enhance Vapor Chemical Deposition, PECVD)成长二氧化矽(Silicon Dioxide, SiO2),并使用反应性离子蚀刻(Reactive Ion Etching, RIE)作选择性蚀刻后得到具高均匀性侧壁保护层(side wall passivation)作选择性成长,并对样品作空间解析阴极射线萤光(Cathodoluminescence, CL)影像作讨论。另外变温光激发萤光(Temperature Dependent Photoluminance, TDPL)随着温度变化量测中,从发光能量随温度的变化可以得到半极化面于成长时具较小的铟丛集以致等效载子局限程度也较极化平面(0001)小,从拟合曲线得出从极化平面的22 meV下降至接近0 meV;而内部量子效率(Internal Quantum Efficiency, IQE)也较高,从22% 提升至30%;且使用时间解析光激发萤光(Time-Resolved Photoluminescence, TRPL)量测显示半极化面多重子阱结构的辐射复合时间远比极化面短,在低温从85 ns 下降至 0.21 ns,归因于量子局限史塔克效应(Quantum Confine Stark Effect, QCSE)减缓,而在变温时间解析光激发萤光(Temperature Dependent Time-Resolved Photoluminescence, TD-TRPL)计算得到半极化面绿光、黄绿光及琥珀色光于近室温及室温时仍具有二维激子 (2D exciton) 发光特性,也代表着属于量子阱贡献发光。随后,我们使用时域有限差分法(Finite-Difference Time-Domain, FDTD)计算,计算得到具奈米结构之发光元件比传统平面及具图形化蓝宝石基板的发光元件,提升了147%的光取出效率(Light Extraction Efficiency, LEE)。
最后,我们把半极化面及极化面的发光二极体完成,并使用电激发萤光(Electroluminescence, EL)量测分析出L-I-V曲线外,并作出半高宽(Full Width at Half Maximum, FWHM)及峰波长随电流从664 nm蓝移至524 nm,从半极化面奈米金字塔及空间解析阴极射线萤光得到发光方式,及使用有限元素法(Finite Element Method, FEM)模拟结果,并得到一致的结果。
In this thesis, we presented high indium content of green, olivine, amber emission semipolar {10-11} GaN-based nanopyramid light emitting diodes (LEDs) grown on c-plane GaN nanorod using selective area growth (SAG).
First, we deposited silicon dioxide (SiO2) on GaN nanorod by plasma enhance chemical vapor deposition (PECVD), and the selective etching was used by Reactive Ion Etching (RIE). The side wall passivation layer formed from upper two step. Then, GaN nanopyramid was grown on nanorod by metal-organic chemical-vapor deposition (MOCVD) using SAG technique. We use spatial resolved cathodoluminescence (CL) to analysis the emission region and have a discussion. In the measurement of temperature dependent photoluminance (TDPL), the less localize state in semipolar plane emission energy verses temperature, the degree of polarize effect is about 22 meV of conversional structure and closed to zero of semipolar plane, the higher internal quantum efficiency (IQE) of 22% to 30% from the integral PL intensity. And the faster radiative lifetime by reducing the quantum confine Stark effect (QCSE) by the time-resolved photoluminesce (TRPL). Calculating the radiative lifetime by IQE and dynamic carrier lifetime, the semipolar green, olivine and amber, the dimensional of exciton emission in nanostructure will be fitted. Then, we use finite-difference time-domain (FDTD) to simulate the light extraction efficiency (LEE) enhancement of the conversional of pattern sapphire substrate (PSS) c-plane LED is about 45% and nanopyramid LED is about 147%.
Finally, the L-I-V curves of nanopyramid LEDs were investigated by electroluminescence (EL) measurement. The emission peak was shifted from 664 nm to 524 nm and full-width at half maximum (FWHM) as function of injection current will be discussed. The emission region of nanopyramid will change by increasing the injection current, and it is the same result with finite element method (FEM) simulation.
URI: http://140.113.39.130/cdrfb3/record/nctu/#GT070050532
http://hdl.handle.net/11536/40173
显示于类别:Thesis