Simulation of near-infrared photodiode detectors based on β-FeSi_2/4H-SiC heterojunctions

In this paper,we propose a near-infrared p-type β-FeSi2/n-type 4H-SiC heterojunction photodetector with semiconducting silicide(β-FeSi2) as the active region for the first time.The optoelectronic characteristics of the photodetector are simulated using a commercial simulator at room temperature.The results show that the photodetector has a good rectifying character and a good response to near-infrared light.Interface states should be minimized to obtain a lower reverse leakage current.The response spectrum of the β-FeSi2/4H-SiC detector,which consists of a p-type β-FeSi2 absorption layer with a doping concentration of 1×1015cm-3 and a thickness of 2.5 μm,has a peak of 755 mA/W at 1.42 μm.The illumination of the SiC side obtains a higher responsivity than that of the β-FeSi2 side.The results illustrate that the β-FeSi2/4H-SiC heterojunction can be used as a near-infrared photodetector compatible with near-infrared optically-activated SiC-based power switching devices.     

一种新型双吸收层光探测器的设计和分析

PIN光探测器是光纤通信系统和网络中的关键器件.量子效率和响应带宽是衡量光探测器性能的重要指标,并且这两个参数都与器件的吸收层密切相关.为了提高光探测器的性能,提出了一种新型双吸收层光探测器(即PINIP结构),利用侧腐蚀工艺减小双吸收层光探测器吸收层的结面积.对其性能进行了理论研究,结果表明该器件的量子效率达到了93％,同时响应带宽达到了26 GHz,比传统结构的双吸收层光探测器提高了44％.     

Fiber‐Based Flexible All‐Solid‐State Asymmetric Supercapacitors for Integrated Photodetecting System

Integrated nanodevices with the capability of storing energy are widely applicable and have thus been studied extensively. To meet the demand for flexible integrated devices, all‐solid‐state asymmetric supercapacitors that simultaneously realize energy storage and optoelectronic detection were fabricated by growing Co₃O₄ nanowires on nickel fibers, thus giving the positive electrode, and employing graphene as both the negative electrode and light‐sensitive material. The as‐assembled integrated systems were characterized by an improved energy storage, enhanced power density (at least by 1860 % enhanced) by improving the potential window from 0–0.6 V to 0—1.5 V, excellent photoresponse to white light, and superior flexibility of both the fiber‐based asymmetric supercapacitor and the photodetector. Such flexible integrated devices might be used in smart and self‐powered sensory, wearable, and portable electronics.     

化学气相沉积法制备InSe纳米片及其近红外光探测性能

采用化学气相沉积法在云母衬底上制备了二维InSe纳米片, 研究了生长温度对二维InSe纳米片晶相、 形貌、 尺寸及厚度的影响. 构筑了基于二维InSe纳米片的光探测器并研究了其光探测性能, 结果表明, 在808 nm的近红外光辐照下, 其光响应度为1.5 A/W, 外量子效率为230%, 可探测度为3.1×10 ⁸ Jones(1 Jones=1 cm·Hz ^1/2·W ^-1), 上升和衰减时间分别为0.5 和0.8 s.     

动静态监测光纤光栅传感信号的实验研究

基于可调谐光纤TF Fabry-Pent（FP）滤波扫描传感光纤Bragg光栅（FBG）反射峰的原理．提出一种新颖的探测方法,分别从动静态两方面监测传感FBG反射谱与TF F-P透射谱的合成谱。实验中．通过加载到TF F-P滤波器的驱动信号的不同,在静态监测下,模拟并分析了光信号功率与转化电压的趋势图以及多次实验中探测到最大信号时两者的关系;用双踪示波器动态实时监测并分析了经光电探测（PD）及其放大调理电路转换后的电压变化信号。实验结果表明．PD探测的最大值与传感FBG反射峰对应。经过标定后的系统分辨率可达1pm,测量精度为0．01nm。     

基于PdSe2/GaAs异质结的高灵敏近红外光伏型探测器的制备和图像传感的应用

本文制备了一种基于PdSe₂/GaAs异质结的高灵敏近红外光电探测器,该探测器是通过将多层PdSe₂薄膜转移到平面GaAs上制成的. 所制备的PdSe₂/GaAs异质结器件在808 nm光照下表现出明显的光伏特性,这表明近红外光电探测器可以用作自驱动器件. 进一步的器件分析表明,这种杂化异质结在零偏电压和808 nm光照下具有1.16×10⁵的高开关比. 光电探测器的响应度和比探测度分别约为171.34 mA/W和2.36×10¹¹ Jones. 而且,该器件显示出优异的稳定性和可靠的重复性. 在空气中2个月后,近红外光电探测器的光电特性几乎没有下降,这归因于PdSe₂的良好稳定性. 最后,基于PdSe₂/GaAs的异质结器件还可以用作近红外光传感器.     

掺杂对2H-MoTe2光电特性影响的第一性原理研究

MoTe₂是一种非空间反演对称性半导体,由线性偏振光照射,在无偏压条件下可以直接产生光电流,但是非常微弱.掺杂可以改变电子能带结构和降低空间反演对称性,从而有效的增强光电流.本文基于非平衡格林函数-密度泛函理论,采用第一性原理,计算了本征、Nb掺杂、Ti掺杂和W掺杂2H-MoTe₂的能带结构、透射谱和光电流.能带结构表明：Nb掺杂使半导体2H-MoTe₂能带穿越费米能级,转变为金属特性;Ti和W掺杂减小了2H-MoTe₂的带隙,能带没有穿越费米能级,依然为半导体.掺杂都降低2H-MoTe₂的反演对称对称性,从本征的D_3h转变为C_s.从而在线偏振光的照射下可以有效的提高2H-MoTe₂的光电流.同时,发现掺杂可以提高单层2H-MoTe₂在低光子能量下的消光比,如Nb和Ti掺杂单层2H-MoTe₂分别在光子能量1.1 eV和1.2 eV处取得39.48和28.48的高消光比...     

Mid-infrared InAsSb-based nBn photodetectors with AlGaAsSb barrier layers – Grown on GaAs,using an interfacial misfit array,and on native GaSb

InAsSb-based nBn photodetectors were fabricated on GaAs, using the interfacial misfit (IMF) array growth mode, and on native GaSb. At −0.1 V operating bias, 200 K dark current densities of 1.4 × 10⁻⁵ A cm⁻² (on GaAs) and 4.8 × 10⁻⁶ A cm⁻² (on GaSb) were measured. At the same temperature, specific detectivity (D^*) figures of 1.2 × 10¹⁰ Jones (on GaAs) and 7.2 × 10¹⁰ Jones (on GaSb) were calculated. Arrhenius plots of the dark current densities yielded activation energies of 0.37 eV (on GaAs) and 0.42 eV (on GaSb). These values are close to the 4 K bandgap of the absorption layers (0.32–0.35 eV) indicating diffusion limited dark currents and small valence band offsets. Significantly, these devices could be used for mid-infrared focal plane arrays operating within the temperature range of cost-effective thermoelectric coolers.     

特殊图案透明欧姆接触微结构提高谐振腔增强型光探测器的响应性能

为解决谐振腔增强型(RCE)光探测器的耦合效率和响应速率的矛盾,提出了采用特殊图案透明欧姆接触的微结构及其制备工艺方案,从而使得在器件入光面积不变的情况下,欧姆接触部分的总面积显著减小,在不影响器件量子效率的前提下达到减小电容、提高响应速率的目的。在台面面积为50μm×50μm的情况下,获得了18 GHz的响应带宽。研制的谐振腔增强型光探测器的响应速率得到了显著的提高。     

An integrated 0.35 μm CMOS optical receiver with clock and data recovery circuit

This paper presents an integrated optical receiver that operates at 1 Gb/s in a standard 0.35 μm digital CMOS technology. The receiver consists of an integrated CMOS photodetector, a transimpedance amplifier (TIA) followed by a post-amplification stage and a dual-loop clock and data recovery (CDR) circuit. At a wavelength of 860 nm, the circuit requires an average light input power of −19.7 dBm to obtain a bit-error rate (BER) of 10⁻¹². The complete receiver consumes a total power of approximately 155 mW from a 3.3-V supply. The core circuit area is 0.85×1.32 mm².