Author Affiliations
Abstract
1 State Key Laboratory on High Power Semiconductor Lasers, Changchun University of Science and Technology, Changchun 130022, China
2 Nanofabrication Facility, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China
GaN has been widely used in the fabrication of ultraviolet photodetectors because of its outstanding properties. In this paper, we report a graphene–GaN nanorod heterostructure photodetector with fast photoresponse in the UV range. GaN nanorods were fabricated by a combination mode of dry etching and wet etching. Furthermore, a graphene–GaN nanorod heterostructure ultraviolet detector was fabricated and its photoelectric properties were measured. The device exhibits a fast photoresponse in the UV range. The rising time and falling time of the transient response were 13 and 8 ms, respectively. A high photovoltaic responsivity up to 13.9 A/W and external quantum efficiency up to 479% were realized at the UV range. The specific detectivity D* = 1.44 × 1010 Jones was obtained at –1 V bias in ambient conditions. The spectral response was measured and the highest response was observed at the 360 nm band.
Journal of Semiconductors
2022, 43(6): 062804
长春理工大学 高功率半导体激光国家重点实验室, 长春 130000
为了降低微盘腔半导体激光器工作时有源区的温度, 提升封装的可靠性, 基于Ansys Workbench有限元分析分别对AlN, WCu10, SiC, 石墨烯, 以及CVD金刚石过渡热沉封装的蜗线型微盘腔半导体激光器进行了热特性分析, 得到了器件工作时的温度分布以及热应力、热应变分布。结果显示, SiC封装器件的有源区温度较AlN和WCu10封装器件分别降低了2.18, 3.078℃, 并在五种过渡热沉封装器件中表现出最低的热应力, 器件热应变最小。SiC过渡热沉封装可以有效降低微盘腔半导体激光器工作时的有源区温度, 同时减少封装应力与器件应变, 从而提高器件的散热能力和可靠性。计算结果对半导体激光器单管散热及阵列集成散热均有指导意义。
微盘腔半导体激光器 过渡热沉 ANSYS热分析 热应力 micro-disk cavity semiconductor laser transition heat sink ANSYS thermal analysis thermal stress
长春理工大学高功率半导体激光国家重点实验室, 吉林 长春 130022
湿法氧化工艺是垂直腔面发射激光器(VCSEL) 制备过程中极为关键的技术,但目前氧化工艺的稳定性和可控性仍有待完善。针对氧化过程中的核心因素——氧化温度进行深入研究,通过设置对照实验,探究了氧化温度对氧化速率及氧化孔形状的作用规律,这对精确控制氧化孔的尺寸和形貌并改善器件的电光特性具有重要意义。同时根据AlGaAs氧化反应机理,优化设计了氧化温控曲线,实验结果表明,通过该氧化温控氧化的样品具有非常良好的热稳定性,整体结构可靠性高。
激光器 半导体激光器 垂直腔面发射激光器 湿法氧化 氧化温度 氧化孔
长春理工大学高功率半导体激光国家重点实验室, 吉林 长春 130022
在氧化物限制型垂直腔面发射激光器制备中,刻蚀GaAs/AlGaAs时因异质型材料常出现选择性内蚀现象,这会直接影响后续的氧化工艺及电极钝化的效果。针对因选择性内蚀而出现的“镂空”现象,对湿法刻蚀工艺和干法刻蚀工艺进行详细研究,研究结果表明通过调整刻蚀液体积配比和感应耦合等离子体(ICP)刻蚀下电极射频功率可有效消除“镂空”现象。湿法刻蚀中,当刻蚀液H3PO4-H2O2-H2O各物质体积配比为1∶1∶10时,得到了陡直度较好且光滑的侧壁。ICP干法刻蚀时,通过改变下电极RF功率可调整腔室内的化学刻蚀和物理刻蚀的动态平衡,在下电极射频功率为100 W时,“镂空”现象基本消失,且侧壁陡直度大于80°。
激光技术 垂直腔面发射激光器 湿法刻蚀 感应耦合等离子体刻蚀 选择性内蚀 镂空
长春理工大学高功率半导体激光国家重点实验室， 吉林 长春 130022
研究了一种2 μm波段GaSb基亚波长光栅反射镜，讨论了亚波长光栅的各参数对反射谱的影响。对于中心波长为2 μm的TM模式，反射镜具有大宽带和极高的反射率，反射带宽与中心波长之比大于26%(反射率大于99%)，波长为1.895~2.08 μm时，反射率达到99.9%以上，带宽达185 nm，同时TE模的反射率低于垂直腔面发射半导体激光器的激射条件(反射率小于95%)。该结构的各个参数所允许的制作容差较大，有利于在垂直腔面发射半导体激光器上的单片集成。
光栅 反射镜 垂直腔面发射激光器 锑化镓 激光与光电子学进展
2017, 54(7): 070501
长春理工大学高功率半导体激光国防科技国家重点实验室, 吉林 长春 130022
根据分布布拉格反射镜(DBR)的工作原理，优化量子阱(QW)和DBR结构，采用Crosslight 计算机模拟软件模拟了垂直腔面发射半导体激光器(VCSEL)的反射谱和QW增益谱，确定QW组分、厚度以及DBR的对数。采用分子束外延技术外延生长并制备了850 nm顶发射VCSEL。测试结果表明，阱宽为5 nm的In0.075Ga0.925As/Al0.35Ga0.65As QW，在室温下激射波长在840 nm左右，设计的顶发射VCSEL结构通过Ocean Optics Spectra Suite软件验证，得到室温下的光谱中心波长在850 nm附近，证实了结构设计的正确性。
激光器 垂直腔面发射激光器 量子阱 分布布拉格反射镜 反射率
长春理工大学高功率半导体激光国家重点实验室, 吉林 长春 130022
垂直腔面发射激光器(VCSEL)具有低阈值电流、圆形光斑、高调制带宽、易于单纵模激射以及高密度二维光集成等优势。在实际应用中,单横模VCSEL是光通信、高速局域网、光互连等许多应用领域的理想光源。在分析VCSEL的结构特性和模式特性的基础上,详述了单横模VCSEL近年来取得的重要进展,分析了各种单横模技术的优势与不足,概述了器件广阔的应用前景及仍待解决的问题。
激光器 半导体激光器 垂直腔面发射激光器 单模 激光与光电子学进展
2013, 50(10): 100003
Author Affiliations
Abstract
InGaAs/GaAs vertical-cavity surface-emitting lasers (VCSELs) are fabricated by a thermal selective wet-oxidation confinement technique. Post-oxidation annealing in a nitrogen environment at high temperatures is then conducted to improve the performance of the oxide-confined InGaAs/GaAs VCSELs. The optimum post-oxidation annealing conditions are determined by changing the furnace temperature and annealing time. Compared with a unannealed laser device, the light output power increases by about 12%. An aging test is carried out to examine the reliability of the annealed oxide-confined VCSEL device. The temperature dependence of the lasing wavelength of the annealed oxide-confined VCSELs is also investigated.
250.5960 Semiconductor lasers 250.7260 Vertical cavity surface emitting lasers 140.7260 Vertical cavity surface emitting lasers Chinese Optics Letters
2012, 10(12): 122501
Author Affiliations
Abstract
National Key Laboratory on High Power Semiconductor Lasers, Changchun University of Science and Technology, Changchun 130022, China
The enlargement of the emitting aperture is usually one of the important methods of increasing verticalcavity surface-emitting laser (VCSEL) optical output power. However, in a VCSEL with a larger aperture, the inhomogeneity in the injected current often causes inhomogeneous or even no emission. To solve this problem and to increase VCSEL output power, as well as to improve its thermal characteristics, we develop a new type of injected VCSEL with a larger aperture and a reticular electrode, where the conventional circular injection electrode of the P side is turned into a reticular one, and the heat sink is on the N side. The tests of the new VCSEL show an improvement in homogeneity in not only the injected current but also the emission intensity. The optical output power is also considerably increased, and the device optoelectronic performance is improved.
垂直腔面发射半导体激光器 网状注入电极 近场发光均匀性 发射光强 光电转换效率 140.0140 Lasers and laser optics 140.7260 Vertical cavity surface emitting lasers 250.7260 Vertical cavity surface emitting lasers 140.5960 Semiconductor lasers Chinese Optics Letters
2010, 8(8): 773
