InGaZnO-based photoelectric synaptic devices for neuromorphic computing

Photoelectric synaptic devices could emulate synaptic behaviors utilizing photoelectric effects and offer promising prospects with their high-speed operation and low crosstalk. In this study, we introduced a novel InGaZnO-based photoelectric memristor. Under both electrical and optical stimulation, the device successfully emulated synaptic characteristics including excitatory postsynaptic current (EPSC), paired-pulse facilitation (PPF), long-term potentiation (LTP), and long-term depression (LTD). Furthermore, we demonstrated the practical application of our synaptic devices through the recognition of handwritten digits. The devices have successfully shown their ability to modulate synaptic weights effectively through light pulse stimulation, resulting in a recognition accuracy of up to 93.4%. The results illustrated the potential of IGZO-based memristors in neuromorphic computing, particularly their ability to simulate synaptic functionalities and contribute to image recognition tasks.

Performance Analysis of Compound Parabolic Concentration Photothermal and Photoelectricity Device for Soil Heating in Facility Agriculture

It is difficult for solanum crops to grow continuously during winter in severe cold regions. Thus, a soil heating system for facility agriculture based on solar concentration technology was proposed, and a novel compound parabolic concentration photothermal and photoelectricity device(CTPV) equipped in the system was designed to address this problem. In accordance with the structure of the device, LightTools optical software was selected to analyze the variation trend of the light escape rate of the device with the diff erent incident angles. On the basis of the calculation results, an experimental test system was used to investigate the relationship of the air temperature of the inlet and the outlet, total output power of the solar cells, and photothermal and photoelectricity efficiency of the device with the operation time during a sunny day. Research results reveal that the light escape rate of the device is 5.36% at an incidence angle of 12°. At a velocity of 1.5 m/s, the maximum air temperature of the outlet can reach 55.6 ℃, and the total output power of the solar cells is 474.4 W. The variation of the total power of the solar cells is consistent with the simulation results. The maximum instantaneous heat collection and the maximum photothermal and photoelectricity efficiency of the device are 306 W and 60.4%, respectively, and the average efficiency is 44.9%. This study can serve as a reference for compound parabolic concentration technology applied for soil heating in facility agricultural soil heating systems.

In-fiber photoelectric device based on graphene-coated tilted fiber grating

Graphene and related two-dimensional materials have attracted great research interests due to prominently optical and electrical properties and flexibility in integration with versatile photonic structures.Here,we report an in-fiber photoelec-tric device by wrapping a few-layer graphene and bonding a pair of electrodes onto a tilted fiber Bragg grating(TFBG)for photoelectric and electric-induced thermo-optic conversions.The transmitted spectrum from this device consists of a dense comb of narrowband resonances that provides an observable window to sense the photocurrent and the electrical injection in the graphene layer.The device has a wavelength-sensitive photoresponse with responsivity up to 11.4 A/W,allowing the spectrum analysis by real-time monitoring of photocurrent evolution.Based on the thermal-optic effect of electrical injection,the graphene layer is energized to produce a global red-shift of the transmission spectrum of the TF-BG,with a high sensitivity approaching 2.167×10^(4)nm/A^(2).The in-fiber photoelectric device,therefore as a powerful tool,could be widely available as off-the-shelf product for photodetection,spectrometer and current sensor.

Thickness effect on solar-blind photoelectric properties of ultrathinβ-Ga_(2)O_(3)films prepared by atomic layer deposition

Theβ-Ga_(2)O_(3)films with different thicknesses are prepared by an atomic layer deposition system.The influence of film thickness on the crystal quality is obvious,indicating that the thicker films perform better crystal quality,which is verified from x-ray diffraction(XRD)and scanning electron microscope(SEM)results.The Ga_(2)O_(3)-based solar blind photodetectors with different thicknesses are fabricated and studied.The experimental results show that the responsivity of the photodetectors increases exponentially with the increase of the film thickness.The photodetectors with inter-fingered structure based on 900 growth cyclesβ-Ga_(2)O_(3)active layers(corresponding film thickness of 58 nm)exhibit the best performances including a low dark current of 134 fA,photo-to-dark current ratio of 1.5×10^(7),photoresponsivity of 1.56 A/W,detectivity of 2.77×10^(14)Jones,and external quantum efficiency of 764.49%at a bias voltage of 10 V under 254-nm DUV illumination.The photoresponse rejection ratio(R_(254)/R_(365))is up to 1.86×10^(5).In addition,we find that the photoelectric characteristics also depend on the finger spacing of the MSM structure.As the finger spacing decreases from 50μm to10μW,the photoresponsivity,detectivity,and external quantum efficiency increase significantly.

Mn^(4+) activated phosphors in photoelectric and energy conversion devices

Owing to their high luminous efficiency and tunable emission in both red light and far-red light regions,Mn^(4+)ion-activated phosphors have appealed significant interest in photoelectric and energy conversion devices such as white light emitting diode(W-LED),plant cultivation LED,and temperature thermometer.Up to now,Mn^(4+)has been widely introduced into the lattices of various inorganic hosts for brightly redemitting phosphors.However,how to correlate the structure-activity relationship between host framework,luminescence property,and photoelectric device is urgently demanded.In this review,we thoroughly summarize the recent advances of Mn^(4+)doped phosphors.Meanwhile,several strategies like co-doping and defect passivation for improving Mn^(4+)emission are also discussed.Most importantly,the relationship between the protocols for tailoring the structures of Mn^(4+)doped phosphors,increased luminescence performance,and the targeted devices with efficient photoelectric and energy conversion efficiency is deeply correlated.Finally,the challenges and perspectives of Mn^(4+)doped phosphors for practical applications are anticipated.We cordially anticipate that this review can deliver a deep comprehension of not only Mn^(4+)luminescence mechanism but also the crystal structure tailoring strategy of phosphors,so as to spur innovative thoughts in designing advanced phosphors and deepening the applications.

On the Physical Process and Essence of the Photoelectric Effect

A hundred years ago, Planck and Einstein and others created quantum theories or quantum mechanics while they explained the photoelectric effect. Planck and Einstein empirically obtained a statistical relationship between the energy of light quantum and the frequency of light but have not studied the physical process and essence of the photoelectric effect, so some photoelectric phenomena are difficult to be explained by existing quantum mechanics currently. In this paper, a dynamical process of orthogonal interaction between a photon and an electron to form a new state of matter in photoelectric effect experiments is studied so finding that the Planck constant is a product value of the mass, length, and velocity of a high-energy particle. The dynamics of the orthogonal collision of matter (particles) can not only give the physical process and essence of the photoelectric effect, but also have great significance for the further development of quantum mechanics. It can physically explain phenomena such as wave-particle duality and quantum entanglement in the motion of high-energy particles. Its prospects can be widely used in cosmic physics, macro physics, and micro physics.

Effect of thickness of antimony selenide film on its photoelectric properties and microstructure

Antimony selenide(Sb2Se3) films are widely used in phase change memory and solar cells due to their stable switching effect and excellent photovoltaic properties. These properties of the films are affected by the film thickness. A method combining the advantages of Levenberg–Marquardt method and spectral fitting method(LM–SFM) is presented to study the dependence of refractive index(RI), absorption coefficient, optical band gap, Wemple–Di Domenico parameters, dielectric constant and optical electronegativity of the Sb2Se3films on their thickness. The results show that the RI and absorption coefficient of the Sb2Se3films increase with the increase of film thickness, while the optical band gap decreases with the increase of film thickness. Finally, the reasons why the optical and electrical properties of the film change with its thickness are explained by x-ray diffractometer(XRD), energy dispersive x-ray spectrometer(EDS), Mott–Davis state density model and Raman microstructure analysis.

Study on the Reparative Effect of Peptide RW3 Binding Active Collagen after Photoelectric Skincare

The photoelectric microneedle treatment instrument is also widely used due to the rapid development of medical cosmetology in China in recent years. It also causes a lot of skin discomfort after the consumers carry out such projects. This study, which combines small molecule active peptides (RW3) and active collagens and imitates the photoelectric treatment through in vitro and in vivo experiment, finds that small molecule active peptides (RW3) and active collagens have different improvement effects on cell proliferation, migration, anti-UV damage, inhibition of ear swelling and inflammation in mice, repair of UV damage and skin damage caused by microneedles. .

基于纳米墨水法制备用于太阳能电池吸收层的CuInS_(x)Se_(2-x)薄膜

以无机盐作为金属源(InCl_(3)、CuCl以及CS_(2)),采用溶剂热法制备CuInS_(2)纳米粒子,进一步采用易热解的铜、铟、硫金属有机前体作为可降解配体成膜交联剂,交联剂包覆铜铟硫纳米粒子得到前驱物墨水,然后通过旋涂法制备CuInS_(2)薄膜,最后对CuInS_(2)薄膜进行硒化,得到的CuInS_(x )Se_(2-x)(CISS)吸光层。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、热重(TG)和霍尔效应测试系统对CISS薄膜的结构和性质进行了研究。结果表明:硒化后的薄膜晶粒尺寸变大,仍为黄铜矿结构。霍尔效应分析表明,所制备的CISS薄膜可用于薄膜太阳能电池的吸收层。

光电损伤后的皮肤特点及其护理

光电治疗通过启动皮肤的创伤修复过程,起到治疗疾病和皮肤美容的作用。本文总结了不同类型光电治疗后皮肤急性损伤期的变化,梳理术后皮肤损伤修复的过程和特点,以及术后皮肤护理方案的原则,拟减少术后不良反应的发生以及促进术后皮肤修复,减少停工期,提升患者满意度。

基于以太网技术的光电信号检测系统

针对光信号检测传输速率低、传输距离短及检测成本高等问题,结合EP4CE115F29C7N型芯片,设计基于以太网的光电信号检测系统。该系统将光电信号采集模块采集到的信号通过AD7606采样并进行预处理后存储到片外SDRAM,同时在UDP/IP协议基础上设计以太网通信模块,将数据通过数据包的方式发送到上位机,并基于LabVIEW设计光信号采集监控系统,实现对上传数据的滤波和实时检测。通过对比输入信号和LabVIEW监控系统显示信号的一致性,验证了系统的正确性。实验结果表明:该系统可以减少光检测信号远距离传输的数据损耗,提高光电信号的检测效率,有较好的实时性和可读性,且程序移植灵活,节约并缩短了光电检测成本和系统开发时间。

ITO/AgNWs/ITO薄膜的制备及其性能研究

随着显示面板向超大尺寸、超高清、可触控的方向发展,单一的氧化铟锡(ITO)薄膜难以满足显示器件越来越高的光电性能要求,因此复合导电薄膜得以发展。本文制备了以二维银纳米线(AgNWs)导电网络嵌入ITO薄膜形成的ITO(222)/AgNWs/ITO(400)复合薄膜结构,系统研究了AgNWs添加量和上层ITO薄膜溅射温度对复合薄膜结构与光电性能的影响,AgNWs金属导电网络不仅提升了薄膜的电学性能,还保持了优良的光学性能。结果表明,在旋涂600μL的AgNWs分散液、上层ITO薄膜的溅射温度为175℃时,制备的复合ITO薄膜方阻为7.13Ω/□,在550 nm处透过率为91.52%,且品质因数为57.82×10^(-3)Ω^(-1),实现了超低电阻率和高可见光透过率复合ITO薄膜的制备。

基于反馈机制的光子微波信号级联滤波方法

光子微波通信过程中,受噪声影响造成带宽变窄,降低了通信效率。为了优化光子微波通信质量,提出基于反馈机制的光子微波信号级联滤波方法。利用形态学腐蚀和膨胀去除信号模糊程度后,将相似度较高的信号聚集为连续区域,完成微波信号去噪。选用卡尔曼滤波器对微波信号测量噪声初次滤波,使用均值滤波以及双门限输出方案二次滤波双路光电反馈下生成的微波信号。通过两种滤波器的级联处理,去除微波信号中不同的杂波,实现窄线宽光子微波信号级联滤波。实验结果表明,所提方法级联滤波波动幅度小,能够平稳输出滤波结果,且不同温度下的级联滤波衰减特性相对平稳。

以太网物理层芯片光电特性测试研究

当前,以太网物理层芯片在诸多应用领域不可或缺,对以太网物理层芯片的功能性能要求也越来越高,因此,如何进行芯片功能性能方面的光电特性验证是亟待解决的问题。主要介绍了以太网物理层芯片验证的技术现状,提出符合以太网物理层芯片功能性能应用需求的光电特性测试方法,采用测试仪器(如示波器、逻辑分析仪、网络矢量分析仪等)和验证板卡对网络中物理接口的数据传输电特性和光特性进行测试,测试结果表明提出的测试方法达到了测试要求,满足了功能性能应用需求,进而提高了国产高可靠以太网物理层芯片验证的技术手段。

机载光电复合旋转连接器设计技术研究

针对机载外挂平台设备系统光电信号旋转传输的使用需求,传统产品存在小型化、轻量化不足及高空环境下高电压易打火等问题,本文提出了机载光电复合旋转连接器一体化成型设计方法,通过中心轴与绝缘片、电刷架与绝缘片一体化结构设计,电接触可靠性及小偏角光纤准直器高效耦合设计,解决了传统光电旋转连接器无法满足机载设备狭小安装空间的小型化及耐高电压等技术难题,研制出了1光5电复合旋转连接器产品,能够满足高空18000 m环境下光电信号动态传输的使用要求,同时,产品随整机通过地面和飞行测试,效果良好。

基于天塞主镜的多尺度长焦成像系统设计

针对提升多尺度成像系统的分辨率以满足对远距离目标精确识别的需求,从提升主镜焦距的角度出发,本文提出一种基于天塞结构主镜的多尺度长焦成像系统设计,分析了为满足次级镜头的线性排布而需要对主镜添加的两个约束条件,针对次级镜头阵列中随离轴角增加使系统在对应视场成像质量下降的问题,对邻近区域次级镜头进行协同优化,同时在离轴位置次级镜头的优化中应用自由曲面面型完成像差校正。所设计系统不同视场区域成像的MTF曲线一致性较好,表明系统在全视场范围内成像质量理想。采用天塞结构主镜设计的多尺度成像系统,其空间分辨率达14μrad,相较于共心球透镜的多尺度系统有显著提高。

通识选修课程光电技术导论课程思政研究与实践

以面向非工专业开设的通识选修课程光电技术导论为例,围绕课程的知识目标、能力目标和素质目标,深入分析课程知识点,知识点所蕴含的思政元素,知识形成过程中的价值理念和科学方法,知识应用过程中涌现的创新实践、协作奋斗和工匠精神,从教学理念、教学内容、教学策略上全方面探讨思想政治教育元素的有机融入方法。给出具体思政案例设计思路和设计方法,从学科特色、社会应用、专业成就及家国情怀等方面着手,将思政元素有机融入课堂教学,为高校将特色学科特色课程引入非本学科专业通识选修教学中,在价值引领、知识教育和能力培养的有机统一上提供探索和实践经验。

光电测量设备线性自抗扰跟踪控制研究

为了实现光电测量设备的精确跟踪控制,考虑模型参数不确定性、外界扰动等因素,从实际靶场应用角度出发,提出了双闭环PD与线性自抗扰(LADRC)相结合的跟踪控制方法。首先建立光电跟踪控制系统数学模型,设计外环PD位置控制器与内环LADRC速度控制器,搭建线性扩张状态观测器实现对系统总扰动的实时估计。通过仿真对比实验验证了PD-LADRC控制策略的有效性。结果表明:在正弦引导跟踪下基于PD-LADRC算法设备稳态误差≤0.469′,随机误差均方根值≤18.9″,具有准确的跟踪控制精度和良好的抗扰动能力。

基于MLE的靶场光电经纬仪高精度定位方法研究

为解决靶场光电经纬仪现用交会定位解算模型作用范围小、与目标实际位置偏差大等问题,提高目标航迹解算精度和模型的适应范围,根据目标跟踪距离和测角误差分量关系,建立了经纬仪空间测量误差模型,优化了异面交会定位加权系数。基于最大似然估计(Maximum Likelihood Estimate,MLE)理论,提出了一种新的更高精度的定位方法,并推导了精度估算公式。详细分析了交会角度、跟踪距离和测角精度对定位误差的影响。试验证明,该方法较现用定位方法适用测量区域增加一倍以上,定位精度提高20%,更适合多测站、不等精度、远距离跟踪等工程场景,具有推广价值。

战斗部破片光电测速系统设计

战斗部破片的飞行速度是体现其性能指标的重要参数;针对目前在战斗部破片速度参数测试中存在对测试环境要求高,测试面积小,设备结构易被破片误击而损坏,成本昂贵等问题,设计了非接触式战斗部破片光电测速系统,包含原向反射膜、反射式光电探测装置、光电转换电路、信号处理电路及测速装置;阐述了系统结构组成和测速原理,通过反射式光电探测装置与光电转换电路,将得到的光信号转换为电信号,利用集成信号处理电路对电信号滤波放大,比较整形处理,由FPGA,STM32及其他外设组成的测速装置自动处理数据输出并显示战斗部破片的飞行速度结果;实验结果表明:该系统能够可靠,稳定地完成战斗部破片速度的测量任务;与传统测速系统相比,具有不受限于环境,测试区域大,易维护,低成本,操作简单等优势。