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表面菱形孔795 nm VCSEL的偏振特性
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作者 付秋雪 孙玉润 +3 位作者 于淑珍 范屹梁 仇伯仓 董建荣 《半导体技术》 CAS 北大核心 2024年第7期609-617,共9页
795 nm垂直腔面发射激光器(VCSEL)作为铷基芯片级原子钟(Rb-CSAC)的光源,其输出光的偏振不稳定会降低Rb-CSAC的稳定度和精确度。为了满足Rb-CSAC对795 nm VCSEL偏振稳定的需求,设计了一种具有表面菱形孔的偏振稳定的795 nm VCSEL。通过... 795 nm垂直腔面发射激光器(VCSEL)作为铷基芯片级原子钟(Rb-CSAC)的光源,其输出光的偏振不稳定会降低Rb-CSAC的稳定度和精确度。为了满足Rb-CSAC对795 nm VCSEL偏振稳定的需求,设计了一种具有表面菱形孔的偏振稳定的795 nm VCSEL。通过有限时域差分(FDTD)法计算了VCSEL的偏振特性,结果表明VCSEL的顶部分布式布拉格反射镜(DBR)在表面菱形孔的长轴和短轴方向具有不同的反射率。反射率高的偏振模式阈值增益低,成为VCSEL优先激射的主导偏振模式。为进一步提高VCSEL的偏振抑制比(OPSR),将VCSEL的氧化孔制作成尺寸为5.5μm×4.1μm的菱形。对不同长、短轴的表面菱形孔795 nm VCSEL进行偏振测试,结果表明,当表面菱形孔的尺寸为4μm×6μm,且菱形氧化孔的长轴与表面菱形孔的长轴相互垂直时,VCSEL的OPSR可达到16.22 dB。 展开更多
关键词 垂直腔面发射激光器(VCSEL) 表面菱形孔 偏振控制 芯片级原子钟(CSAC) 分布式布拉格反射镜(DBR)
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增厚DBR型894 nm窄线宽VCSEL
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作者 范屹梁 孙玉润 +3 位作者 付秋雪 于淑珍 仇伯仓 董建荣 《半导体技术》 CAS 北大核心 2024年第5期449-454,共6页
垂直腔面发射激光器(VCSEL)是芯片级原子钟(CSAC)的主流光源,其光束质量会影响CSAC的各项性能。扩展VCSEL内部有效腔长能够以压缩冷腔线宽的方式压窄器件最终辐射激光的线宽,从而可以减小CSAC短时间内的计时频率噪声。根据所计算的VCSE... 垂直腔面发射激光器(VCSEL)是芯片级原子钟(CSAC)的主流光源,其光束质量会影响CSAC的各项性能。扩展VCSEL内部有效腔长能够以压缩冷腔线宽的方式压窄器件最终辐射激光的线宽,从而可以减小CSAC短时间内的计时频率噪声。根据所计算的VCSEL表面反射谱,将VCSEL中4层下分布式布拉格反射镜(DBR)的厚度由常规的四分之一波长增加至404 nm,压缩了VCSEL冷腔线宽,并生长了对应的外延结构,制备了通过增厚DBR扩展有效腔长的894 nm窄线宽VCSEL。测试结果表明,研制的VCSEL在90℃下波长为893.1 nm,功率为0.335 mW,线宽约为32 MHz,且具有稳定的偏振特性。 展开更多
关键词 垂直腔面发射激光器(VCSEL) 芯片级原子钟(CSAC) 有效腔长 分布式布拉格反射镜(DBR) 线宽
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凝胶剂量计调强放射治疗三维剂量验证初探 被引量:3
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作者 王飞 何承发 +8 位作者 杨进 于飞 刘艳 赵云 孙玉润 周东 席善斌 许发月 李明 《核电子学与探测技术》 CAS CSCD 北大核心 2011年第3期327-330,共4页
调强放射治疗(IMRT)是最先进的放射治疗技术之一,因其复杂性和三维治疗计划系统的逆向计算的优化算法在某些方面还不够成熟,所以治疗前必须进行剂量验证以确保治疗剂量的准确性。本文使用聚合物凝胶剂量计对调强放射治疗三维剂量的验证... 调强放射治疗(IMRT)是最先进的放射治疗技术之一,因其复杂性和三维治疗计划系统的逆向计算的优化算法在某些方面还不够成熟,所以治疗前必须进行剂量验证以确保治疗剂量的准确性。本文使用聚合物凝胶剂量计对调强放射治疗三维剂量的验证进行初步探索。用丙烯酰胺、明胶、交联剂、除氧剂在常氧条件下制备凝胶剂量计,使用调强放射治疗计划对球形烧瓶(模拟辐照体模)进行辐照,^(60)Coγ射线对同批次制备的剂量计试管进行剂量刻度。其后进行磁共振成像得到刻度曲线和模拟靶区的二维、三维剂量分布。结果表明,新型的凝胶剂量计对剂量的响应能够准确地呈现出靶区形状和三维剂量分布,高剂量梯度区分辨明显。 展开更多
关键词 凝胶剂量计 三维剂量验证 调强放射治疗 磁共振成像
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高能电子辐照对三结GaAs激光电池特性的影响 被引量:1
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作者 韩堰辉 孙玉润 +4 位作者 王安成 施祥蕾 李彬 孙利杰 董建荣 《半导体技术》 CAS 北大核心 2023年第2期170-176,共7页
研究了能量为1 MeV的电子辐照对三结GaAs激光电池(LPC)性能的影响。不同剂量电子辐照后三结GaAs LPC光照下的I-V特性测试结果表明,三结GaAs LPC短路电流、开路电压和最大输出功率的衰减随电子辐照剂量的提高而增大。通过测量不同波长激... 研究了能量为1 MeV的电子辐照对三结GaAs激光电池(LPC)性能的影响。不同剂量电子辐照后三结GaAs LPC光照下的I-V特性测试结果表明,三结GaAs LPC短路电流、开路电压和最大输出功率的衰减随电子辐照剂量的提高而增大。通过测量不同波长激光照射下三结GaAs LPC的宽电压范围I-V曲线,确定了各子电池对应的光生电流,结果显示各子电池光生电流衰减随辐照剂量增加而不同程度地增大,越靠近衬底的子电池电流衰退越严重。利用wxAMPS软件模拟了各子电池光生电流随缺陷密度的变化关系,结合实验和模拟结果得到了各子电池辐照后的缺陷密度及缺陷引入率,结果表明各子电池受电子辐照后的缺陷引入率大致相同,约为6.7。可通过优化各结子电池厚度达到提高三结GaAs LPC抗辐照性能的目的。 展开更多
关键词 三结激光电池(LPC) 电子辐照损伤 缺陷密度 电学性能退化 抗辐照加固
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图案化GaAs衬底外延InP局域表面成核层生长
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作者 戚永乐 张瑞英 +6 位作者 张震 王岩岩 朱健 孙玉润 赵勇明 董建荣 王庶民 《半导体技术》 CAS CSCD 北大核心 2015年第6期448-454,共7页
使用光学显微镜、原子力显微镜和微区喇曼光谱对在纳球光刻图案化GaAs衬底的孔洞区进行金属有机化学气相沉积(MOCVD)进而对InP成核层进行了研究。实验结果表明,该局域表面InP的成核层生长和孔洞的大小、方向、位置关系不大,与MOCVD的生... 使用光学显微镜、原子力显微镜和微区喇曼光谱对在纳球光刻图案化GaAs衬底的孔洞区进行金属有机化学气相沉积(MOCVD)进而对InP成核层进行了研究。实验结果表明,该局域表面InP的成核层生长和孔洞的大小、方向、位置关系不大,与MOCVD的生长条件相关。与渐变缓冲层生长相比,在InP的成核层中没有出现穿透位错,其结晶质量随着温度的升高而提高,但其表面粗糙度会随着温度的升高而增加,这个现象可能和它的3D岛状生长有关。AFM测试结果表明,提高V/III比可以在较低的温度下抑制其表面粗糙度降至纳米量级。微区喇曼光谱测试表明,在适当条件生长下可获得InP成核层的二维生长方式。该研究为进一步基于ART机理在二维图案化GaAs衬底开展InP异质外延研究奠定基础。 展开更多
关键词 图形化衬底 GaAs/InP异质外延 表面形貌 粗糙度 应力
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1310nm InGaAsP多结激光电池
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作者 秦杰 孙玉润 +3 位作者 于淑珍 王安成 尹佳静 董建荣 《半导体技术》 CAS 北大核心 2023年第8期658-664,共7页
针对现有1 310 nm激光电池(LPC)的低输出电压难以满足电子器件供电需求的问题,采用多结叠层结构设计,制备了六结InGaAsP 1 310 nm LPC并进行了测试。测试结果表明,在功率密度为57.5 W/cm^(2)的激光照射下,六结LPC的光电转换效率为31.0%... 针对现有1 310 nm激光电池(LPC)的低输出电压难以满足电子器件供电需求的问题,采用多结叠层结构设计,制备了六结InGaAsP 1 310 nm LPC并进行了测试。测试结果表明,在功率密度为57.5 W/cm^(2)的激光照射下,六结LPC的光电转换效率为31.0%,开路电压(Voc)超过3.6 V,实现了高的输出电压。六结LPC的短路电流随温度的升高而降低,当激光功率密度为13.25 W/cm^(2)时,Voc的温度系数为-9.61 mV/K。复合电流严重影响LPC的填充因子和光电转换效率,利用双二极管模型拟合了变温I-V曲线,研究了内部参数与温度的变化关系,表明陷阱辅助隧穿过程是导致LPC高复合电流的主要原因。 展开更多
关键词 激光电池(LPC) 多结叠层 1310 nm 复合电流 陷阱辅助隧穿
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氧化孔径对VCSEL功耗和效率的影响
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作者 李荣伟 孙玉润 +2 位作者 于淑珍 尹佳静 董建荣 《半导体技术》 CAS 北大核心 2020年第11期867-873,共7页
高温导致垂直腔面发射激光器(VCSEL)的输出功率滚降,功率转换效率降低。为了研究高环境温度中VCSEL的温度稳定性和功率转换效率,通过测试不同环境温度下不同氧化孔径波长850 nm VCSEL的P-I-V曲线,发现在相同注入电流下,随着环境温度的升... 高温导致垂直腔面发射激光器(VCSEL)的输出功率滚降,功率转换效率降低。为了研究高环境温度中VCSEL的温度稳定性和功率转换效率,通过测试不同环境温度下不同氧化孔径波长850 nm VCSEL的P-I-V曲线,发现在相同注入电流下,随着环境温度的升高,VCSEL的氧化孔径越大,功率损耗增加越明显,而小氧化孔径的VCSEL功率损耗受温度的影响很小。室温下VCSEL的氧化孔径越大,功率转换效率越高,但当环境温度高于一定值时,中等氧化孔径(约5μm)的VCSEL反而具有更高的功率转换效率。通过分析温度对VCSEL微分电阻等功率损耗的影响,发现适当降低氧化孔径,有利于实现VCSEL在高环境温度中高的功率转换效率。 展开更多
关键词 垂直腔面发射激光器(VCSEL) 氧化孔径 功率损耗 功率转换效率 微分电阻
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Control of symmetric properties of metamorphic In0.27Ga0.73As layers by substrate misorientation
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作者 于淑珍 董建荣 +4 位作者 孙玉润 李奎龙 曾徐路 赵勇明 杨辉 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第3期408-413,共6页
Asymmetry in dislocation density and strain relaxation has a significant impact on device performance since it leads to anisotropic electron transport in metamorphic materials. So it is preferred to obtain metamorphic... Asymmetry in dislocation density and strain relaxation has a significant impact on device performance since it leads to anisotropic electron transport in metamorphic materials. So it is preferred to obtain metamorphic materials with symmetric properties. In this paper, we grew metamorphic Ino.27Gao.73As epilayers with symmetric low threading dislocation density and symmetric strain relaxation in two (110) directions using InA1GaAs buffer layers on 7° misoriented GaAs (001) substrates. To understand the control mechanism of symmetric properties of Ino.27Gao.73As layers by the substrate miscut angles, Ino.27Gao.73As grown on 2° and 15° misoriented substrates were also characterized as reference by atomic force microscopy, transmission electron microscopy, and high resolution triple axis x-ray diffraction. The phase separation and interaction of 60° misfit dislocations were found to be the reasons for asymmetry properties of Ino.27Gao33As grown on 2° and 15° substrates, respectively. Photoluminescence results proved that the Ino.27G°ao.73As with symmetric properties has better optical properties than the Ino.27Gao.73As with asymmetric properties at room temperature. These results imply that high quality metamorphic Ino.27Gao.73As can be achieved with controllable isotropic electron transport property. 展开更多
关键词 Ino.27Gao.73As substrate misorientation SYMMETRY MOCVD
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Dislocation distributions and tilts in Al(Ga)InAs reverse-graded layers grown on misorientated GaAs substrates
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作者 何洋 孙玉润 +2 位作者 赵勇明 于淑珍 董建荣 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第3期550-553,共4页
Compositionally undulating step-graded Al(Ga)InxAs (x = 0.05-0.52) buffers with the following InP layer were grown by metal-organic chemical vapor deposition (MOCVD) on (001) GaAs with a 15° miscut. The d... Compositionally undulating step-graded Al(Ga)InxAs (x = 0.05-0.52) buffers with the following InP layer were grown by metal-organic chemical vapor deposition (MOCVD) on (001) GaAs with a 15° miscut. The dislocation dis- tribution and tilts of the epilayers were examined using x-ray rocking curve and (004) reciprocal space maps (RSM) along two orthogonal (110) directions. The results suggested that such reverse-graded layers have different effects on a and 13 dislocations. A higher dislocation density was observed along the [ 110] direction and an epilayer tilt of - 1.43° was attained in the [1-10] direction when a reverse-graded layer strategy was employed. However, for conventional step-graded samples, the dislocation density is normally higher along the [1-10] direction. 展开更多
关键词 Al(Ga)InAs reverse-graded layers dislocation distribution tilt
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Low specific contact resistivity to graphene achieved by AuGe/Ni/Au and annealing process
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作者 于淑珍 宋焱 +3 位作者 董建荣 孙玉润 赵勇明 何洋 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第11期571-575,共5页
Low metal-graphene contact resistance is important in making high-performance graphene devices.In this work,we demonstrate a lower specific contact resistivity of Au0.88Ge0.12/Ni/Au-graphene contact compared with Ti/A... Low metal-graphene contact resistance is important in making high-performance graphene devices.In this work,we demonstrate a lower specific contact resistivity of Au0.88Ge0.12/Ni/Au-graphene contact compared with Ti/Au and Ti/Pt/Au contacts.The rapid thermal annealing process was optimized to improve AuGe/Ni/Au contact resistance.Results reveal that both pre- and post-annealing processes are effective for reducing the contact resistance.The specific contact resistivity decreases from 2.5 × 10^-4 to 7.8 × 10^-5 Ω·cm^2 by pre-annealing at 300 ℃ for one hour,and continues to decrease to 9.5 × 10^-7 H·cm2 after post-annealing at 490 ℃ for 60 seconds.These approaches provide reliable means of lowering contact resistance. 展开更多
关键词 annealing resistivity annealed lithography contacts doping alloyed lowering align methacrylate
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1.31μm InGaAsP/InGaAlAs TM偏振高速激光器的优化设计
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作者 曾徐路 于淑珍 +4 位作者 李奎龙 孙玉润 赵勇明 赵春雨 董建荣 《激光与光电子学进展》 CSCD 北大核心 2014年第2期102-108,共7页
报道了一种以InGaAsP(阱)/InGaAlAs(垒)量子阱为有源区的1.31μmTM偏振高速激光器。以1%张应变的In_(0.49)Ga_(0.51)As_(0.79)P_(0.21)作为阱层,0.5%压应变的InGaAlAs作为垒层,计算了由不同势垒带隙(1.309、1.232、1.177、1.136、1.040 ... 报道了一种以InGaAsP(阱)/InGaAlAs(垒)量子阱为有源区的1.31μmTM偏振高速激光器。以1%张应变的In_(0.49)Ga_(0.51)As_(0.79)P_(0.21)作为阱层,0.5%压应变的InGaAlAs作为垒层,计算了由不同势垒带隙(1.309、1.232、1.177、1.136、1.040 eV)构成的五种多量子阱的发光特性,和由其构成的激光器的器件特性。数值模拟分析表明,采用适度小的势垒带隙,既能将载流子有效限制在有源区,又可以得到载流子在量子阱间的均匀分布,从而改善量子阱的发光特性和激光器的性能参数。该仿真对研制低阈值电流、高特征温度和大调制带宽的InGaAsP/InGaAlAs应变补偿量子阱激光器具有指导意义。 展开更多
关键词 激光器 TM偏振 数值模拟 INGAASP INGAALAS
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InGaAsP/InGaAs tandem photovoltaic devices for four-junction solar cells 被引量:1
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作者 赵勇明 董建荣 +5 位作者 李奎龙 孙玉润 曾徐路 何洋 于淑珍 杨辉 《Journal of Semiconductors》 EI CAS CSCD 2015年第4期86-89,共4页
Lattice-matched lnGaAs(P) photovoltaic devices were grown on lnP substrates by metal-organic chem- ical vapor deposition. InGaAsP/InGaAs ( 1.07/0.74 eV) dual-junction (D J) solar cells were fabricated and charac... Lattice-matched lnGaAs(P) photovoltaic devices were grown on lnP substrates by metal-organic chem- ical vapor deposition. InGaAsP/InGaAs ( 1.07/0.74 eV) dual-junction (D J) solar cells were fabricated and charac- terized by quantum efficiency and I-V measurements. The open circuit voltage, short circuit current density, fill factor, and efficiency of lnGaAsP/lnGaAs DJ solar cell are 0.977 V, 10.2 mA/cm2, 80.8%, and 8.94%, respectively, under one sun illumination of the AM 1.5D spectrum. For the lnGaAsP/lnGaAs DJ solar cell, with increasing con- centration, the conversion efficiency first increases steadily and reaches 13% around 280 suns, and finally decreases due to the drop in fill factor at higher concentration ratios. These experimental results demonstrate the promising prospect of GaInP/GaAs/lnGaAsP/lnGaAs four-junction solar cells. 展开更多
关键词 lIattice-matched InGaAs(P) solar cells MOCVD
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A six-junction GaAs laser power converter with different sizes of active aperture 被引量:3
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作者 SUN Yu-run 《Optoelectronics Letters》 EI 2017年第1期21-24,共4页
We investigate a novel Ga As-based laser power converters(LPCs) grown by metal-organic chemical vapor deposition(MOCVD),which uses a single monolithic structure with six junctions connected by tunnel junctions to obta... We investigate a novel Ga As-based laser power converters(LPCs) grown by metal-organic chemical vapor deposition(MOCVD),which uses a single monolithic structure with six junctions connected by tunnel junctions to obtain a high output voltage. The LPCs with diameters of active aperture of 2 mm and 4 mm were fabricated and tested. The test results show that under an 808 nm laser,two LPCs both show an open circuit voltage of above 6.5 V. A maximum power conversion efficiency of 50.2% is obtained by 2 mm sample with laser power of 0.256 W,and an output electric power of 1.9 W with laser power of 4.85 W is obtained by 4 mm sample. The performances of the LPCs are deteriorated under illumination of high flux,and the 4 mm sample shows a higher laser power tolerance. 展开更多
关键词 aperture junction illumination converter diameters MOCVD sizes etching connected photovoltaic
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Dose-rate dependence of optically stimulated luminescence signal
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作者 卫平强 陈朝阳 +2 位作者 范艳伟 孙玉润 赵云 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2010年第10期1-4,共4页
Optically stimulated luminescence (OSL) is the luminescence emitted from a semiconductor during its exposure to light. The OSL intensity is a function of the total dose absorbed by the sample. The dose-rate dependen... Optically stimulated luminescence (OSL) is the luminescence emitted from a semiconductor during its exposure to light. The OSL intensity is a function of the total dose absorbed by the sample. The dose-rate dependence of the OSL signal of the semiconductor CaS doped Ce and Sm was studied by numerical simulation and experiments. Based on a one-trap/one-center model, the whole OSL process was represented by a series of differential equations. The dose-rate properties of the materials were acquired theoretically by solving the equations. Good coherence was achieved between numerical simulation and experiments, both of which showed that the OSL signal was independent of dose rate. This result validates that when using OSL as a dosimetry technique, the dose-rate effect can be neglected. 展开更多
关键词 optically stimulated luminescence DOSE-RATE numerical simulation radiation measurement
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Influence of GaInP ordering on the performance of GaInP solar cells
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作者 于淑珍 董建荣 +4 位作者 赵勇明 孙玉润 李奎龙 曾徐路 杨辉 《Journal of Semiconductors》 EI CAS CSCD 2016年第7期31-34,共4页
CuPt-type ordering with undesirable properties always occurs in GaInP at growth conditions that are very close to those leading to the highest quality material in metal organic chemical vapor deposition. In this work,... CuPt-type ordering with undesirable properties always occurs in GaInP at growth conditions that are very close to those leading to the highest quality material in metal organic chemical vapor deposition. In this work, highly disordered GaInP with high crystalline quality was obtained by optimizing growth conditions. Room- temperature and low-temperature photoluminescence (PL) spectra of A1GalnP/GaInP/A1GaInP double heterostruc- tures (DHs) reveal that the band edge emission intensity is enhanced by optimizing growth temperature, V/III ratio, and reactor pressure at the expense of low energy peak originating from spatially indirect recombination due to the ordering-related defects. The DH sample with less ordering-related defects demonstrates a longer effective minority carrier lifetime, consequently, the GaInP solar cell shows a significant improvement in the performance. 展开更多
关键词 MOCVD GAINP ORDERING solar cell
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