高功率共振腔增强型光电探测器研究进展

共振腔增强型光电探测器(RCE-PD)作为一种新型光电探测器,具有高量子效率、高响应度和波长选择性等优点,成为目前光纤通信领域中最为重要的探测器之一.在数字和模拟光传输系统中,高功率探测器由于具有高信噪比、低插入损耗等优点,在国际上越来越受到重视.综述了这两种探测器的基本结构、发展状况,展望了其发展前景等.指出高功率共振腔增强型光电探测器将是今后最有发展前途的探测器.     

Ag-catalyzed GaSb nanowires for flexible near-infrared photodetectors

High-quality narrow bandgap semiconductors nanowires (NWs) challenge the flexible near-infrared (NIR) photodetectors in next-generation imaging, data communication, environmental monitoring, and bioimaging applications. In this work, complementary metal oxide semiconductor-compatible metal of Ag is deposited on glass as the growth catalyst for the surfactant-assisted chemical vapor deposition of GaSb NWs. The uniform morphology, balance stoichiometry, high-quality crystallinity, and phase purity of as-prepared NWs are checked by scanning electron microscopy, energy dispersive X-ray spectroscopy, high-resolution transmission electron microscopy, and X-ray diffraction. The electrical properties of as-prepared NWs are studied by constructing back-gated field-effect-transistors, displaying a high I_on/I_off ratio of 10⁴ and high peak hole mobility of 400 cm²/(V·s). Benefiting from the excellent electrical and mechanical flexibility properties, the as-fabricated NW flexible NIR photodetector exhibits high sensitivity and excellent photoresponse, with responsivity as high as 618 A/W and detectivity as high as 6.7 × 10¹⁰ Jones. Furthermore, there is no obvious decline in NIR photodetection behavior, even after parallel and perpendicular folding with 1200 cycles.     

A Paper-Based Wearable Photodetector for Simultaneous UV Intensity and Dosage Measurement

Photodetectors, which convert the light signal into other forms of signal, have been under the spotlight of research for many years because they are widely applied in monitoring, communication, and imaging. Most of the currently available photodetectors can output electrical signals to indicate the transient light intensity, while some display color change to reveal the absorbed light dosage. However, there is no device that can tell the transient light intensity and accumulated light dosage at the same time. Here, a paper-based wearable photodetector that can simultaneously measure transient light intensity and accumulated light dosage is reported. The phosphomolybdic acid/citric acid system, whose color change can be observed by the naked eye, is designed as the photochromic material to combine with photodetective materials (using 2D Sr₂Nb₃O₁₀ and ZnO nanoparticle as examples) on paper. Such paper-based photodetector fully utilizes natural hygroscopicity and softness of paper, showing decent flexibility. Its optoelectronic signal remains stable even after 1000 cycles of bending. To the best of one's knowledge, this is the first photodetector that can tell light intensity and dosage simultaneously. This work introduces a new type of wearable photodetector by structure design and material selection, shedding light on more novel works for convenient and practical photodetection.     

谐振腔增强型光探测器的高速响应性能研究

高速长波长光探测器是高速光纤通信系统和网络的关键器件，它要求光探测器具有宽的频率响应带宽和高量子效率。常用的PIN光探测器由于量子效率和高速性能均受到吸收层厚度的牵制，使得二者相互制约，成为一对矛盾。谐振腔增强型(RCE)光探测器为这一矛盾的解决提供了有效的方案。基于谐振腔增强型光探测器的实际设计和制作模型，分析了器件吸收层中的光场分布，并将其运用于载流子的连续方程，从理论上详细地分析了器件的高速响应特性，给出了计算结果。针对研制的高速长波长谐振腔增强型光探测器，进行了理论分析和实际器件测试的结果比较，得到了比较一致的结果。     

High-Responsivity Natural-Electrolyte Undersea Photoelectrochemical Photodetector with Self-Powered Cu@GaN Nanowires Network

Undersea optical communication (UOC) has been considered as the most potential next-generation underwater wireless communication technology for ocean exploration. Photodetector is the essential component in UOC system, however, the harsh undersea environment like light attenuation and seawater corrosivity restricts the applications of conventional photodetectors. Herein, a novel natural-electrolyte self-powered photoelectrochemical (PEC) photodetector based on core-shell structured Cu@GaN nanowires (NWs) network is demonstrated and direct utilization of seawater. High quality GaN shell is encapsulated on the Cu NWs network through Ga-coating and high temperature nitridation processes. A Schottky junction along radial direction has formed at the Cu/GaN interface due to the outward diffusion of Cu into the GaN layer. Such a structure provides narrowed band detection on blue light as well as efficient carrier separation. A self-powered undersea PEC photodetector is designed with a mini-pipes connected device chamber, which allows direct indrawing of seawater and blue channel light communication (458 nm). This photodetector works stably for UOC in both shallow and deep-sea conditions in Pacific Ocean area. It shows a high responsivity up to 5.04 mA W⁻¹ and rapid response time of 0.68 ms. This photodetector can be easily integrated to marine equipment without waterproof packaging for the future energy-saving UOC.     

A 1.5 Gb/s monolithically integrated optical receiver in the standard CMOS process

A monolithically integrated optical receiver, including the photodetector, has been realized in Chartered 0.35 μm EEPROM CMOS technology for 850 nm optical communication. The optical receiver consists of a differential photodetector, a differential transimpedance amplifier, three limiting amplifiers and an output circuit. The experiment results show that the receiver achieves an 875 MHz 3 dB bandwidth, and a data rate of 1.5 Gb/s is achieved at a bit-error-rate of 10~(-9). The chip dissipates 60 mW under a single 3.3 V supply.     

用于下一代数据中心的改进型单行载流子光探测器的研究

本文研究并提出一种具有电场增强的混合吸收层结构的单行载流子光探测器(electric-enhanced modified uni-traveling carrier photodetector, EE-MUTC-PD)。该结构通过吸收区渐变掺杂增强了光探测器吸收区电场,将吸收区分为部分耗尽和耗尽两个部分,使得光生电子漂移通过吸收区的同时光生空穴会在弛豫时间内被收集,有效解决了单行载流子光探测器(uni-traveling carrier photodetector, UTC-PD)在低光功率注入下不能保持较高带宽的问题,同时实现了高响应度,可用于下一代800 Gb/s光通信系统中。     

Large-Area Freestanding Bi2S3 Nanofibrous Membranes for Fast Photoresponse Flexible IR Imaging Photodetector

Films with excellent flexibility and mechanical stability are important for flexible and wearable devices. However, most films reported are prepared on substrates, and the synthesis of freestanding flexible films remains a challenge. Herein, a freestanding Bi₂S₃ nanofibrous membrane (NFM) is successfully prepared via a one-step hydrothermal method, which is self-assembled from ultralong Bi₂S₃ nanowires (NWs) over a length of millimeter-scale crisscrossing each other. Significantly, the Bi₂S₃ NFM can be bent or clipped into an arbitrarily desired form. Based on the freestanding Bi₂S₃ NFM, an IR photodetector is fabricated, depicting a robust responsivity of 2.23 (2.06) µA W⁻¹ under 850 (940) nm illumination. The Bi₂S₃ NFM photodetector exhibits a relatively fast response time (47.1 ms), which is attributed to high-speed carrier transport efficiency in the NWs network. Under the bending states, the device still exhibits excellent detection performance, maintaining more than 86% of the initial photocurrent even after 1000 bending-flattening times. The robust photoresponse of the Bi₂S₃ NFM photodetector after 2 months of storage in air and after 1 week in the bending state illustrates its excellent air stability and flexible detection ability. Besides, the photodetector can clearly identify the target image, indicating widespread potential applications in flexible and wearable fields.     

宽谱光源平均波长测试系统光路设计仿真

利用像元分辨率公式和高斯光束传输理论,设计了一种基于线阵InGaAs光电探测器的宽谱光源平均波长测试系统光路结构。在Zemax光学软件中建立了宽谱光源平均波长测试系统的光路模型,并优化了该测试系统的光路结构参数。根据软件仿真建立的光路模型,分析了位置偏差对准直光束平行度及系统光能利用率的影响,得到了相应的变化曲线,为宽谱光源平均波长测试系统的结构设计和装配提供了指导。     

一种渐变掺杂型pin光探测器的高速响应性能研究

高速光探测器是高速光纤通信系统和网络中的关键器件,它要求光探测器具有宽的频率响应带宽和高量子效率。垂直入光型pin光探测器的高速性能和量子效率均受到吸收层厚度的限制。为了改善其高速性能,采用InGaAsP材料作为吸收层以及限制层渐变掺杂的方法,对垂直入光型pin光探测器的高速响应性能进行了理论研究和仿真,结果表明,高速响应达到了40GHz。与不采用渐变掺杂浓度的同种结构光探测器相比,高速响应性能显著提高。     

采用InGaAs或InAlAs缓冲层的高In组分InGaAs探测器结构材料特性

利用气态源分子束外延在InP衬底上生长了具有InxGa1-xAs或InxAl1-xAs连续递变缓冲层的高In组分In0.78Ga0.22As探测器结构.通过原子力显微镜、X射线衍射、透射电子显微镜和光致发光对它们的特性进行了表征和比较.结果表明,具有InxGa1-xAs或InxAl1-xAs缓冲层的结构都能获得较平整的...     

光纤通信有源器件的发展现状

光纤通信技术的飞速发展使其成为当今信息社会的重要支柱。其发展的基石是有源和无源半导体光电子器件。综述了几种主要的有源光电子器件的研究现状及其发展趋势,包括高速调制DFB激光器及其集成芯片、EDFA泵浦源用980 nm半导体高功率激光器、化合物半导体光电探测器、硅基长波长光电探测器等。     

光学瞄准及自动跟踪系统设计

为提高激光通信、激光制导、激光雷达等光电系统的工作可靠性及自动化程度,提出了光学瞄准及自动跟踪系统的设计方案.系统采用四象限光电探测器为前端探测单元,结合自动控制技术和精密步进系统,实现目标激光光斑的自动瞄准和跟踪.介绍了系统的工作原理,并对其进行了硬件设计和控制程序设计.经调试、运行证明,该系统方案可行、简单且易于实现,二维位移的跟踪控制精度可达10μm以下.     

A Novel Method to Simultaneously Measure the Straightness

A precise two--degree--of--freedom measuring system (2DMS) is developed based on single--mode optical fiber, LD, cube corner retroreflector and four--quadrant photodetector (4-Q), and the simultaneous on--line measurement of lateral and vertical direction straightness errors of the linear stage is carried out. The moving part is wireless, which eliminates any errors introduced by pushing and pulling the wires. The sensitivity of the straightness error measurement can be improved by a factor of 2 with the cube corner retroreflector. This fiber- based optically aligned beam is used to establish a reference line for the straightness measurement of any mechanical system. 4--Q detector is used to receive the laser beam. A chip microcomputer is developed to conduct alldata acquisition and signal processing. The beam drift influence can be removed in the greatest extent from the system. The experiments on the measurement system stability,repeatability and its comparison with the HP5528 double--frequency laser interferometer are carried out.     

四象限光电探测器在激光光学系统中的典型应用分析

分析了四象限光电探测器在激光制导、光镊、扫描探针显微镜和空间光通信等激光光学系统中的典型应用。结果表明,四象限光电探测器应用在激光制导中具有高制导精度的优势;应用在光镊系统和扫描探针显微镜中具有纳米级分辨率：应用在空间光通信中具有较高跟踪和定位精度。     

光学玻璃ECT光探测器的设计与实现

介绍了光学玻璃ECT的工作原理,并针对光学玻璃ECT存在的精度问题,分析出光探测器直流偏置会导致比差超限。简要说明了光电二极管原理及电流-电压转换电路,进一步探讨会导致光探测器产生直流偏置的原因及解决办法,测试证明,设计的光探测器能满足光学玻璃ECT精度要求。     

Muscle Fibers Inspired High-Performance Piezoelectric Textiles for Wearable Physiological Monitoring

The next-generation wearable biosensors with highly biocompatible, stretchable, and robust features are expected to enable the change of the current reactive and disease-centric healthcare system to a personalized model with a focus on disease prevention and health promotion. Herein, a muscle-fiber-inspired nonwoven piezoelectric textile with tunable mechanical properties for wearable physiological monitoring is developed. To mimic the muscle fibers, polydopamine (PDA) is dispersed into the electrospun barium titanate/polyvinylidene fluoride (BTO/PVDF) nanofibers to enhance the interfacial-adhesion, mechanical strength, and piezoelectric properties. Such improvements are both experimentally observed via mechanical characterization and theoretically verified by the phase-field simulation. Taking the PDA@BTO/PVDF nanofibers as the building blocks, a nonwoven light-weight piezoelectric textile is fabricated, which hold an outstanding sensitivity (3.95 V N⁻¹) and long-term stability (<3% decline after 7,400 cycles). The piezoelectric textile demonstrates multiple potential applications, including pulse wave measurement, human motion monitoring, and active voice recognition. By creatively mimicking the muscle fibers, this work paves a cost-effective way to develop high-performance and self-powered wearable bioelectronics for personalized healthcare.     

High‐Performance Polypyrrole/Graphene/SnCl2 Modified Polyester Textile Electrodes and Yarn Electrodes for Wearable Energy Storage

Flexible supercapacitors have potential for wearable energy storage due to their high energy/power densities and long operating lifetimes. High electrochemical performance with robust mechanical properties is highly desired for flexible supercapacitor electrodes. Usually, the mechanical properties are improved by choosing high flexible textile substrates but at the much expense of electrochemical performance due to the nonideal contact between conductive materials and textile substrates. Herein, the authors present an efficient, scalable, and general strategy for the simultaneous fabrication of high‐performance textile electrodes and yarn electrodes. It is interesting to find that the conformal reduced graphene oxide (RGO) layer is uniformly and successively painted on the surface of SnCl₂ modified polyester fibers (M‐PEF) via a repeated “dyeing and drying” strategy. The large‐area textile electrodes and ultralong yarn electrodes are fabricated by using RGO/M‐PEF as substrate with subsequent deposition of polypyrrole. This work provides new opportunities for developing high flexible textile electrodes and yarn electrodes with further increased electrochemical performance and scalable production.     

衬底温度及蒸发条件对有机光电探测器性能的影响

为了深入研究p型Si衬底的有机光电探测器的工艺条件对器件光电性能的影响,本文利用Dektak-8型α台阶仪及高分辨率Topometrix Exptorer型原子力显微镜(AFM),对不同衬底温度及蒸发条件下沉积的有机薄膜表面厚度进行了测量;采用拓扑和侧向力接触两种模式,对其表面形貌及其变化规律进行了研究;对制成的光电探测器的光电性能进行了测试分析。结果表明,PTCDA在p-Si(100)表面形成的多晶薄膜呈岛状形态,岛的大小及形貌受制备工艺条件的影响;当衬底温度为50℃、PTCDA的蒸发温度为420℃和蒸发时间为15s时,蒸发薄膜的厚度为135nm;测得器件的最大光电流为92μA,暗电流为7nA。实现了衬底温度及蒸发条件的最佳化。     

GaN紫外光电导探测器的研究

回顾了近几年在 Ga N紫外光电导探测器上的研究进展 ,介绍了不同 Ga N光电导紫外光探测器的制备方法、光电参数及工作机理。