1 上海理工大学 材料科学与工程学院,上海 200093
2 中国科学院上海技术物理研究所 红外物理国家重点实验室,上海 200083
3 上海师范大学 数理学院,上海 200234
4 中国科学院上海技术物理研究所 红外成像材料与器件重点实验室,上海 200083
在平面型InGaAs P-i-N短波红外探测结构中,p型杂质在材料中纵向和横向的扩散是决定pn结位置及其光电性能的主要因素,本文采用扫描电容显微方法(SCM)获得了扩散成结InGaAs/InAlAs像元剖面的二维载流子分布,从而实现对不同扩散条件下pn电场结的精确定位和分析。此外,对于InGaAs/InP探测器,SCM测量揭示了Zn杂质在各功能层中扩散行为的显著差异。在InGaAs吸收区中,Zn的侧向扩散速度是深度方向的3.3倍,远高于其在n-InP帽层中0.67的侧向与深度扩散比,这将对光敏元的边缘电容以及暗电流特性产生影响。
扫描电容显微(SCM) InGaAs平面型探测器 扩散行为 光电流响应 Scanning Capacitance Microscopy(SCM) planar InGaAs detector diffusion behavior photocurrent response
1 上海理工大学 材料科学与工程学院,上海 200093
2 中国科学院上海技术物理研究所 红外物理国家重点实验室,上海 200083
3 上海师范大学 数理学院,上海 200234
4 上海科技大学 物质科学与技术学院,上海 201210
首先从热力学角度讨论减少太阳能光伏结构效率损失,特别是光学熵损失的原理和途径,然后介绍半导体纳米线阵列在降低材料使用率的同时有效实现陷光和降低发射角的结构设计,其中由直径渐变纳米线形成的非周期阵列具有可见到近红外宽波段的导模共振陷光能力,同时极低的发射角大幅度地抑制了自发辐射引起的光子损失,成为有望突破Shockley-Queisser转换效率极限的光伏结构.
太阳能电池 可见至近红外 全向吸收 发射角限制 非均匀纳米线阵列 solar cells visible to near-infrared omnidirectional absorbtion emission angle limit non-uniform nanowire arrays 红外与毫米波学报
2019, 38(4): 04508
1 南通大学 电子信息学院, 江苏 南通 226019
2 中国科学院上海技术物理研究所 红外成像材料和器件重点实验室, 上海 200083
采用扫描电容显微镜分析了平面型PIN In0.52Al0.48As/In0.53Ga0.47As/ In0.52Al0.48As短波红外探测器盲元产生的原因, 利用半导体器件仿真工具Sentaurus TCAD对探测器中的盲元特性进行了模拟, 并利用制备的Au/P-In0.52Al0.48As传输线结构芯片对P电极的欧姆接触进行优化.研究结果表明, P电极与扩散区外的N--In0.52Al0.48As帽层形成导电通道导致了盲元的产生, 优化后Au与P-In0.52Al0.48As帽层之间具有更低的比接触电阻为3.52×10-4 Ω·cm-2, 同时Au在高温快速热退火过程中的流动被抑制, 从而降低了盲元产生的概率.
短波红外探测器 盲元 比接触电阻 Short wavelength infrared detector InGaAs InGaAs Blind pixel Special contact resistivity Au Au
Author Affiliations
Abstract
1 National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China
2 Shanghai Engineering Research Center of Energy-Saving Coatings, Shanghai 200083, China
3 University of Chinese Academy of Sciences, Beijing 100049, China
A new approach is proposed to accurately determine the thickness of films, especially for ultra-thin films, through spectrum-fitting with the assistance of an interference layer. The determination limit can reach even less than 1 nm. Its accuracy is far better than that of the traditional methods. This determination method is verified by experiments, and the determination limit is at least 3.5 nm compared with the results of atomic force microscope (AFM). Furthermore, a double interference-aided spectra fitting method is proposed to reduce the requirements of the determination instruments, which thus allows one to determine the film’s thickness with a low-precision common spectrometer and to greatly lower the cost. It is a very high-precision determination method for on-site and in-situ applications, especially for ultra-thin films.
120.4290 Nondestructive testing 120.4800 Optical standards and testing 220.4840 Testing 120.7000 Transmission Chinese Optics Letters
2016, 14(8): 081203
Author Affiliations
Abstract
School of Physics and Electronics, Central South University, Changsha 410083, China
A low-coherence fiber-optic dynamic light scattering (FODLS) technique is utilized to measure the effective viscosity of colloidal suspensions over a range of temperatures and volume fractions. Based on the single scattering theory, the volume fraction dependency of the effective viscosity can be obtained from the analysis of the single scattering spectra measured using FODLS. Experimental data on the viscous at Brownian short-times of colloidal suspensions are compared with theoretical results. The effective viscosity is in good agreement with the theoretical values by considering the Carnahan–Starling approximation. It is confirmed that the effective short-time viscosity of colloidal suspensions at different volume fractions and temperatures can be measured by the low-coherence FODLS technique.
Chinese Optics Letters
2015, 13(Suppl): S21201
本文针对高浓度散射介质, 用低相干光纤动态光散射技术测量浓悬浮液中多分散颗粒系的粒径及其粒径分布。利用迭代CONTIN算法对实验数据进行反演运算, 得到多分散颗粒系的粒径分布结果。结果表明, 浓悬浮液中多分散颗粒系的峰值粒径测量值与给定的两种标准粒径值相吻合, 其误差在4%之内, 粒径分布曲线中各散射颗粒所反映的散射体光强分布与根据Mie散射计算得到的理论值相吻合。实验结果证明低相干光纤动态光散射实验系统能准确测量浓悬浮液中多分散颗粒粒径及粒径分布。
散射 低相干光纤动态光散射 浓悬浮液 多分散 粒径分布 scattering low-coherence fiber optic dynamic light scattering concentrated suspensions polydisperse Particle size distribution
1 中南大学 物理科学与技术学院,湖南 长沙 410083
2 太原卫星发射中心,山西 五寨 036204
为研究散射光强度随光子在散射媒质中散射光程的变化,基于单散射理论与扩散波光谱理论,采用了低相干动态光散射装置对不同粒径大小的聚苯乙烯悬浮液进行研究。将测量得到的背散射光光场强度谱的线宽与相应的理论计算结果相比较发现,在短光程区域,考虑容器壁附近拖曳效应的影响后,对于不同粒径的颗粒,光程为约5倍粒子平均自由程的区域可看成为单散射区域;对于光程大于225 μm的区域可看成为扩散光波区域。实验结果表明低相干动态光散射法可实现高散射媒质从单散射区域到低次散射再到扩散区域的全光程的可分割的光场强度谱测量。
低相干动态光散射 单散射 扩散波 平均自由程 low-coherence dynamic light scattering single scattering diffusing wave spectroscopy mean-free path length