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Optical properties of ultra-thin InN layer embedded in InGaN matrix for light emitters

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Chinese Physics B 2013年第4期22卷 482-485页

作者：杨薇武翌阳刘宁炀刘磊陈钊胡晓东 State Key Laboratory for Artificial Microstructure and Mesoscopic Physics School of Physics Peking University

We theoretically investigate the optical properties of an ultra-thin InN layer embedded in InGaN matrix for light emitters. The peak emission wavelength extends from ultraviolet （374 nm） to green （536 nm） with InN quantum well thickness increasing from 1 monolayer to 2 monolayers, while the overlap of electron–hole wave function remains at a high level （larger than 90%）. Increase of In content in InGaN matrix provides a better approach to longer wavelength emission, which only reduces the spontaneous emission rate slightly compared with the case of increasing In content of the conventional InGaN quantum well. Also, the transparency carrier density derived from gain spectrum is of the same order as that in the conventional blue laser diode. Our study provides skillful design on the development of novel structure InN-based light emitting diodes as well as laser diodes.

关键词： InN ultra-thin layer spontaneous emission spectra gain laser diodes

光谱拟合反演法制备高显色指数白光LED的研究

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半导体光电 2015年第5期36卷 713-717,721页

作者：李成驰范广涵郭光华陈志涛刘宁炀古志良中南大学物理与电子学院长沙410012 广东省工业技术研究院广州510650

荧光粉受激发产生的白光LED照明光源存在显色指数较低的问题。对此提出一种利用光谱拟合反演高显指目标光谱的方法,针对已知白光LED计算提高该光源所需补充的单色光LED种类及光谱系数。利用光谱拟合方法分析添加不同波段的光谱对白光LE... 详细信息

荧光粉受激发产生的白光LED照明光源存在显色指数较低的问题。对此提出一种利用光谱拟合反演高显指目标光谱的方法,针对已知白光LED计算提高该光源所需补充的单色光LED种类及光谱系数。利用光谱拟合方法分析添加不同波段的光谱对白光LED显指和色温的影响。并通过拟合反演的方法进行补光设计,使用一到两种单色光LED,将冷白光源和中性白光源的显指分别提高至92.3和96.8。实验结果表明,使用红光与蓝绿光、低波长绿光LED补光后,大幅度提高了荧光粉受激发产生的白光LED光源的显色性。

关键词：发光二极管光谱拟合显色指数反演法色温光视效能

Intersubband transitions in Al_(0.82)In_(0.18)N/GaN single quantum well

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Chinese Physics B 2011年第9期20卷 226-231页

作者：王宇宙李丁李磊刘宁炀刘磊曹文彧陈伟华胡晓东 State Key Laboratory of Artificial Microstructure and Mesoscopic Physics School of PhysicsPeking University

The influence of the width of a lattice-matched A10.82In0.18N/GaN single quantum well （SQW） on the absorption coefficients and wavelength of the intersubband transition （ISBT） has been investigated by solving the Schr5dinger and Poisson equations self-consistently. The wavelength of 1-2 ISBT increases with L, the thickness of the single quantum well, ranging from 2.88 ~m to 3.59 ~.m. The absorption coefficients of 1-2 ISBT increase with L at first and then decrease with L, with a maximum when L is equal to 2.6 nm. The wavelength of 1-3 ISBT decreases with L at first and then increases with L, with a minimum when L is equal to 4 nm, ranging from approximately 2.03 p^m to near 2.11 p.m. The absorption coefficients of 1-3 ISBT decrease with L. The results indicate that mid-infrared can be realized by the A10.s2In0.1sN/GaN SQW. In addition, the wavelength and absorption coefficients of ISBT can be adjusted by changing the width of the SQW.

关键词： Alo.s2Ino.lsN/GaN single quantum well optoelectronic devices mid-infrared intersub-band transition

空间限制退火制备自供电p-CuI/u-GaN薄膜异质结蓝-紫光探测器研究

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半导体光电 2024年第5期45卷 700-706页

作者：梁田泓吕军兴刘宁炀尉俊陈志涛宋伟东五邑大学应用物理与材料学院广东江门529020 广东省科学院半导体研究所广州510650

自供电型光电探测器通过内建电场即可完成信号的探测,无需外加电源,具有低功耗、高灵敏度及快速响应等特点,引起了研究者的广泛关注。文章利用简易的真空热升华方法制备出高结晶度的CuI微米颗粒薄膜。进一步利用空间限制退火技术抑制了... 详细信息

自供电型光电探测器通过内建电场即可完成信号的探测,无需外加电源,具有低功耗、高灵敏度及快速响应等特点,引起了研究者的广泛关注。文章利用简易的真空热升华方法制备出高结晶度的CuI微米颗粒薄膜。进一步利用空间限制退火技术抑制了退火过程中CuI分子的纵向扩散,显著改善了薄膜的均匀性和致密性。通过构建p-CuI/u-GaN异质结,实现了具有自供电特性的蓝-紫光探测器。该探测器的响应范围为波长小于420 nm的蓝-紫光波段,在360 nm的紫外光波段具有大响应度(51 mA·W^(-1))、高比探测率(6.1×10^(11)Jones)、较快响应速度(上升时间为32 ms,衰减时间为36 ms)及良好的稳定性。研究结果表明,采用热升华结合空间限制退火技术能够制备出高质量的p-CuI薄膜,p-CuI/u-GaN异质结自供电蓝-紫光探测器为高性能半导体光电探测器件的制备提供了新的方法和途径。

关键词：真空热升华法空间限制退火自供电蓝-紫光探测器

氧分压对磁控溅射β-Ga_(2)O_(3)薄膜结构及光学特性的影响

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半导体光电 2021年第6期42卷 849-853页

作者：董斌何晨光王长安李祈昕李叶林刘宁炀赵维陈志涛广东省科学院半导体研究所广州510650

通过磁控溅射沉积以及高温热退火处理,在5.08 cm(2 inch)c-plane蓝宝石异质衬底上制备出单晶β-Ga_(2)O_(3)薄膜,研究了溅射气氛中氧分压对β-Ga_(2)O_(3)薄膜的晶体结构以及光学特性的影响。通过调控氧分压,获得了具有{-201}晶面族X射... 详细信息

通过磁控溅射沉积以及高温热退火处理,在5.08 cm(2 inch)c-plane蓝宝石异质衬底上制备出单晶β-Ga_(2)O_(3)薄膜,研究了溅射气氛中氧分压对β-Ga_(2)O_(3)薄膜的晶体结构以及光学特性的影响。通过调控氧分压,获得了具有{-201}晶面族X射线衍射峰的β-Ga_(2)O_(3)薄膜,其最大晶粒尺寸达到138 nm,在300~800 nm波段透射率大于80%,最大光学带隙达5.12 eV。最优的薄膜表面粗糙度达0.401 nm, 800 nm波长处折射率为1.94。实验结果表明,降低氧分压有利于溅射粒子动能增大、数量增多,从而提升β-Ga_(2)O_(3)薄膜结晶质量、增加薄膜透射率和光学带隙;适当提高氧分压则有利于改善薄膜表面平整度,并提高致密度。

关键词： β-Ga_(2)O_(3)磁控溅射晶体结构光学特性

p型GaN上Pd/NiO/Al/Ni反射电极欧姆接触的热稳定性研究

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半导体光电 2020年第2期41卷 242-246页

作者：左秉鑫曾昭烩李祈昕李叶林刘宁炀赵维陈志涛李云平中南大学材料科学与工程学院长沙410083 广东省半导体产业技术研究院广州510650 中南大学粉末冶金国家重点实验室长沙410083

研究了p型GaN上Pd/NiO/Al/Ni反射电极欧姆接触的比接触电阻率、热稳定性,以及光学反射率。与传统Pd/Al/Ni电极相比,Pd/NiO/Al/Ni电极的欧姆接触在氮气环境中经300℃下热处理10min后,仍保持低比接触电阻率(小于5×10-4Ω·cm2)和高反射率... 详细信息

研究了p型GaN上Pd/NiO/Al/Ni反射电极欧姆接触的比接触电阻率、热稳定性,以及光学反射率。与传统Pd/Al/Ni电极相比,Pd/NiO/Al/Ni电极的欧姆接触在氮气环境中经300℃下热处理10min后,仍保持低比接触电阻率(小于5×10-4Ω·cm2)和高反射率(大于80%@365nm)。研究获得的优化Pd/NiO层厚度为1nm/2nm,此时的Pd/NiO/Al/Ni反射电极既能形成良好的欧姆接触,拥有低比接触电阻率,又能减少对紫外光的吸收,保持高反射率。研究表明适当的NiO层厚度能够有效地防止热处理过程中上层Al金属向p-GaN表面层的渗入,对于制备高质量的Al基反射电极至关重要。

关键词： GaN 电极材料欧姆接触热稳定性倒装紫外LED芯片

Efficiency droop alleviation in blue light emitting diodes using the InGaN/GaN triangular-shaped quantum well

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Chinese Physics B 2012年第10期21卷 522-526页

作者：陈钊杨薇刘磊万成昊李磊贺永发刘宁炀王磊李丁陈伟华胡晓东 State Key Laboratory for Artificial Microstructure and Mesoscopic Physics School of PhysicsPeking University

The InGaN/GaN blue light emitting diode（LED） is numerically investigated using a triangular-shaped quantum well model,which involves analysis on its energy band,carrier concentration,overlap of electron and hole wave functions,radiative recombination rate,and internal quantum *** simulation results reveal that the InGaN/GaN blue light emitting diode with triangular quantum wells exhibits a higher radiative recombination rate than the conventional light emitting diode with rectangular quantum wells due to the enhanced overlap of electron and hole wave functions（above 90%） under the polarization ***,the efficiency droop is only 18% in the light emitting diode with triangular-shaped quantum wells,which is three times lower than that in a conventional LED.

关键词： efficiency droop alleviation InGaN/GaN triangular quantum well blue light emitting diode

Improvement of doping efficiency in Mg-Al_(0.14)Ga_(0.86)N/GaN superlattices with AlN interlayer by suppressing donor-like defects

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Chinese Physics B 2012年第11期21卷 402-407页

作者：刘宁炀刘磊王磊杨薇李丁李磊曹文彧鲁辞莽万成昊陈伟华胡晓东 State Key Laboratory for Artificial Microstructure and Mesoscopic Physics School of PhysicsPeking University

We investigate the mechanism for the improvement of p-type doping efficiency in Mg-Al0.14Ga0.86N/GaN super- lattices （SLs）. It is shown that the hole concentration of SLs increases by nearly an order of magnitude, from 1.1 × 1017 to 9.3×1017 cm-3, when an AlN interlayer is inserted to modulate the strains. SchrSdinger-Poisson self-consistent calculations suggest that such an increase could be attributed to the reduction of donor-like defects caused by the strain modulation induced by the AlN interlayer. Additionally, the donor-acceptor pair emission exhibits a remarkable decrease in intensity of the cathodoluminescence spectrumlfor SLs with an A1N interlayer. This supports the theoretical calculations and indicates that the strain modulation of SLs could be beneficial to the donor-like defect suppression as well as the p-type doping efficiency improvement.

关键词： superlattice doping efficiency strain modulation nitrogen vacancy

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GaN基垂直结构LED的研究进展

GaN基垂直结构LED的研究进展