n-on-p结构深台面延伸波长InGaAs探测器的ICPCVD钝化工艺

采用ICP刻蚀(inductively coupled plasma etching)工艺制备了深台面n-on-p结构的可响应到2.4μm的延伸波长8×1元线列In Ga As探测器.器件表面采用ICP源激发的N2等离子体进行处理,然后再使用ICPCVD(inductively coupled plasma chemical vapor deposition)沉积一层Si Nx薄膜的钝化工艺.不同面积光敏元器件的电流—电压特性分析显示器件在常温和低温下侧面电流均得到有效抑制,激活能分析显示了器件优异的暗电流特性,在-10 m V偏压下,在200 K和300 K温度下暗电流密度分别为94.2 n A/cm2和5.5×10-4A/cm2.     

Tribotronic Phototransistor for Enhanced Photodetection and Hybrid Energy Harvesting

Tribotronics is a new field developed by coupling triboelectricity and semiconductor, which can drive triboelectric‐charge‐controlled optoelectronic devices by further introducing optoelectronics. In this paper, a tribotronic phototransistor (TPT) is proposed by coupling a field‐effect phototransistor and a triboelectric nanogenerator (TENG), in which the contact‐induced inner gate voltage by the mobile frictional layer is used for modulating the photodetection characteristics of the TPT. Based on the TPT, alternatively, a coupled energy‐harvester (CEH) is fabricated for simultaneously scavenging solar and wind energies, in which the output voltage on the external resistance from the wind driven TENG is used as the gate voltage of the TPT for enhancing the solar energy conversion. As the wind speed increases, the photovoltaic characteristics of the CEH including the short‐circuit current, open‐circuit voltage, and maximal output power have been greatly enhanced. This work has greatly expanded the functionality of tribotronics in photodetection and energy harvesting, and provided a potential solution for highly efficient harvesting and utilizing multitype energy.     

Diketopyrrolopyrrole Organic Thin‐Film Transistors: Impact of Alkyl Substituents and Tolerance of Ethylhexyl Stereoisomers

Bis(thiophen‐2‐yl)‐diketopyrrolopyrrole (DPP) dyes bearing various alkyl substituents at the amide positions (n‐butyl, n‐pentyl, n‐hexyl, n‐heptyl, n‐octyl, 2‐ethylhexyl) and chlorine (Cl), bromine (Br), or cyano (CN) substituents at the thiophene positions have been synthesized and investigated with regard to their molecular and semiconducting properties. Intense absorption, strong fluorescence, and reversible oxidation and reduction processes are common to all of these dyes. Their characterization as organic semiconductors in vacuum‐processed thin‐film transistors reveals p‐channel operation with field‐effect mobilities ranging from 0.01 to 0.7 cm² V^?1 s^?1. The highest mobility is found for the DPP dyes bearing the 2‐ethylhexyl substituents, which is surprising, considering that as a result of the chiral substituents, this material is a mixture of (R,R), (S,S), and (R,S) stereoisomers. The high carrier mobility in the films of the DPPs bearing stereoisomerically inhomogeneous ethylhexyl groups is rationalized here by single‐crystal X‐ray diffraction (XRD) analysis in combination with XRD and atomic force microscopy studies on thin films, which reveal the presence of slightly different 2D layer arrangements for the n‐alkyl and the 2‐ethylhexyl derivatives. For the cyano‐substituted DPPs possessing the lowest LUMO levels, ambipolar transport characteristics are observed.     

Nitrogen‐Doped Graphene Ribbon Assembled Core–Sheath MnO@Graphene Scrolls as Hierarchically Ordered 3D Porous Electrodes for Fast and Durable Lithium Storage

Graphene scroll is an emerging 1D tubular form of graphitic carbon that has potential applications in electrochemical energy storage. However, it still remains a challenge to composite graphene scrolls with other nanomaterials for building advanced electrode configuration with fast and durable lithium storage properties. Here, a transition‐metal‐oxide‐based hierarchically ordered 3D porous electrode is designed based on assembling 1D core–sheath MnO@N‐doped graphene scrolls with 2D N‐doped graphene ribbons. In the resulting architecture, porous MnO nanowires confined in tubular graphene scrolls are mechanically isolated but electronically well‐connected, while the interwoven graphene ribbons offer continuous conductive paths for electron transfer in all directions. Moreover, the elastic graphene scrolls together with enough internal voids are able to accommodate the volume expansion of the enclosed MnO. Because of these merits, the as‐built electrode manifests ultrahigh rate capability (349 mAh g^?1 at 8.0 A g^?1; 205 mAh g^?1 at 15.0 A g^?1) and robust cycling stability (812 mAh g^?1 remaining after 1000 cycles at 2.0 A g^?1) and is the most efficient MnO‐based anode ever reported for lithium‐ion batteries. This unique multidimensional and hierarchically ordered structure design is believed to hold great potential in generalizable synthesis of graphene scrolls composited with oxide nanowires for mutifuctional energy storage.     

智能PID控制算法研究及Matlab实现

针对滞后大、非线性等复杂的系统,常规PID控制算法已无法满足控制任务要求。为解决此类问题,文中提出从智能PID控制中的模糊PID控制、BP神经网络PID控制着手,仿真比较智能PID控制与常规PID控制的控制结果。实验表明,智能PID控制的超调量可达到0,稳定时间也大幅缩短,使系统整体的动静态特性得到了有效地改善。     

灰色数列模型在图像边缘趋势预测中的应用

为了达到跟踪预测刀具图像边缘变化趋势的目的,采用了灰色数列GM（1,1）模型预测拟合直线段斜率数列的方法。在分析灰色数列预测模型的基础上,通过建立了图像边缘点拟合直线斜率数列预测模型,并用建立的模型对一帧刀具图像进行边缘趋势预测,将得到的预测结果与实际值进行比较的试验。并以最大误差分析刀具后续边缘点分布趋势,为图像采集平台进给方向提供依据。根据实验结果,得出采用灰色数列模型预测刀具边缘轮廓方法完全满足平台跟踪刀具边缘轮廓要求的结论。     

基于CDP1854的智能数据适配器设计与使用

异步接收/同步发送数据适配器是PC机与受控终端之间实现信息交换的接口电路。为了实现信息传送,需要将从PC机串口发送来的串行异步信息转换为同步信息发送出去,该适配器可实现异步接收/串行发送,达到PC机控制受控终端的目的。     

温度对CdZnTe载流子输运特性和能谱特性的影响

采用垂直布里奇曼法生长的CdZnTe(CZT)单晶,制备出单平面探测器。在210～300K温度范围内,测试了不同外加偏压作用下探测器的漏电流,并计算了低压下CZT的体电阻率。同时,在不同电场作用下,测试了CZT探测器对未经准直的241 Am@5.48 MeVα粒子脉冲响应信号的上升时间,计算出电子迁移率为1 360cm2/V-1s-1,并进一步推算出电子寿命随温度的变化规律。在220～300K温度范围内,对比了CZT探测器对241 Am@59.5keVγ射线的能谱响应结果,分析了载流子传输特性及器件性能随温度的变化规律。结果表明,在298～253K温度范围内,降低温度可以提高晶体的体电阻率,减少探测器工作时的漏电流,进而提高探测器的能量分辨率;但当温度低于253K时,电子寿命τe加剧减小,此时由上升时间起伏而引起的全能峰的展宽不能被忽略,导致探测器性能恶化。