GaN-based MSM photovoltaic ultraviolet detector structure modeling and its simulation

Based on the principles of metal-semiconductor-metal Schottky barrier photodetectors(MSM-PD), using the carrier rate equations,the circuit simulation model of a GaN-based MSM photovoltaic ultraviolet detector is constructed through an appropriately equivalent process.By using the Pspice analytical function of Cadence soft on the model,the relationship between the photocurrent and the terminal voltage under different UV light powers is analyzed.The result shows that under the given UV power,the photocurrent increases and tends to become saturated gradually as the terminal voltage of the device increases,and that under different UV powers,the photocurrent increases with increasing incident power.Then the analysis of the relationship between the photocurrent and the terminal voltage under the different ratios of interdigital electrode space and width is carried out when the UV power is given.The results show that when the ratio of interdigital electrode space and width(L/W) equals 1,the photocurrent tends to be at a maximum.     

基于物镜耦合的波长-角度共同调制表面等离激元共振传感器

基于棱镜耦合的波长调制表面等离激元共振(SPR)传感器只能在长波段获得较高检测灵敏度,无法兼顾检测范围与检测灵敏度。研究了一种基于物镜耦合激发表面等离激元的波长-角度共同调制的SPR传感装置,使用物镜耦合使角度易于调节,这提高了SPR传感器在短波处的检测灵敏度,从而在较大检测范围内实现了高灵敏度折射率测量。通过理论仿真与实验,使用波长-角度共同调制的SPR传感方法对不同浓度的葡萄糖溶液的折射率进行测量,动态检测范围为4.4×10^-2 RIU,检测灵敏度达到5066.97 nm/RIU。相较于波长调制SPR传感方法,使用波长-角度共同调制的SPR传感方法在检测范围不变的情况下,检测灵敏度提高了2.5倍。该检测方法实现了对折射率高灵敏度、高动态检测范围的快速检测,可广泛应用在生物医学及食品安全等领域。     

可见光与红外融合的汽车抗晕光图像评价方法

为了解决汽车抗晕光场景中,融合图像质量的客观评价与人眼视觉效果不一致的问题,提出了一种新的可见光与红外融合图像质量评价方法,该方法通过设计自适应迭代阈值法自动确定融合图像的晕光临界灰度值,并将融合图像自动分为晕光区和非晕光区.针对晕光区,设计晕光消除度指标评价晕光消除的效果;针对非晕光区,从多方面评价色彩、细节信息的增强效果,并甄选出合适的指标构成完整的图像质量评价体系.为验证该方法的合理性,对采用4种不同算法的融合图像进行评价,实验分析表明,该方法的主客观评价结果一致,适于评判不同可见光与红外融合的抗晕光图像质量及算法的优劣.     

晶格失配对InAsχP1-χ/InP发光特性的影响

采用低压金属有机化学气相沉积(LP-MOCVD)技术,在掺Fe的半绝缘InP衬底上制备了InAs0.157P0.843外延层.利用变温光致发光研究了InAs0.157P0.843外延层在13～300 K温度范围内的发光特性,通过理论分析与计算,证实了在应力作用下InAs0.157P0.843外延层价带顶的轻重空穴带发生了劈裂,并研究了导带底与价带顶轻空穴带之间形成的复合发光峰在应力作用下随温度的变化规律.     

晶格失配对InAsxP1-x/InP发光特性的影响

采用低压金属有机化学气相沉积(LP-MOCVD)技术,在掺Fe的半绝缘InP衬底上制备了InAs_0.157P_0.843 外延层。利用变温光致发光研究了InAs_0.157P_0.843外延层在13~300 K温度范围内的发光特性,通过理论分析与计算,证实了在应力作用下InAs_0.157P_0.843外延层价带顶的轻重空穴带发生了劈裂,并研究了导带底与价带顶轻空穴带之间形成的复合发光峰在应力作用下随温度的变化规律。     

烷基醇聚氧乙烯醚中二噁烷的测定

１引言随着现代工业的发展和人民生活水平的提高，家用洗涤剂的使用范围越来越广，使用量也在不断增加。烷基醇聚氧乙烯醚是液体洗涤剂的有效成份，其合成过程中产生的二噁烷是有害物质，虽其含量较低，但它能通过蒸气形式吸入人体，与眼、皮肤等接触，侵害人的肝、肾、皮肤、眼睛等多个部位，且能在人体内积蓄，给人们的健康造成危害。聚氧乙烯醚中二噁烷的测定尚未见报道。本文采用顶空气相色谱法对烷基醇聚氧乙烯醚中的二噁烷进行测定，选择了顶空条件，以保留值和加入已知物增加峰高法定性，外标法定量，建立了简便、准确、灵敏的分析测…     

GaN基MSM结构光伏型紫外探测器建模及其仿真分析

Based on the principles of metal-semiconductor-metal Schottky barrier photodetectors(MSM-PD), using the carrier rate equations,the circuit simulation model of a GaN-based MSM photovoltaic ultraviolet detector is constructed through an appropriately equivalent process.By using the Pspice analytical function of Cadence soft on the model,the relationship between the photocurrent and the terminal voltage under different UV light powers is analyzed.The result shows that under the given UV power,the photocurre...     

多步旋涂CsPbBr3薄膜复光学常数的椭偏光谱研究

为了研究多步旋涂法制备的CsPbBr₃薄膜的光学常数,以溴化铅和溴化铯为原料,采用多步旋涂法在硅和FTO衬底上制得CsPbBr₃薄膜。利用光弹调制式椭偏光谱仪对硅衬底上的薄膜进行了椭偏光谱分析,使用Tanguy和Tauc-Lorentz 3组合模型对变角度的椭偏光谱进行参数拟合,得到了薄膜光学常数在1.00 eV～5.00 eV范围内的色散关系,并利用荧光发射光谱、吸收谱验证椭偏拟合结果。结果表明,多步旋涂法制备的CsPbBr₃薄膜的光学常数与其它方法相比具有一定的差异性,其中折射率可能与薄膜表面粗糙度呈负相关;椭偏拟合所得带隙为2.3 eV,验证了荧光光谱、吸收谱的计算结果。该研究为多步旋涂法制备的CsPbBr₃薄膜椭偏光谱拟合分析提供了参考。     

两种蒽衍生物类深蓝光材料的合成与发光性能

利用Suzuki偶合反应合成了两种新的蒽衍生物9,10-二(2-联苯基)蒽(BBPA)和9,10-二[2-(α-萘基)苯基]蒽(BNPA),化合物结构通过核磁、质谱及元素分析进行了表征。量子化学计算结果显示,这两种化合物都具有非共面的分子结构,光物理性能主要决定于分子中的蒽结构单元。这两种化合物在二氯甲烷溶液中均可发射高效率的蓝光。BBPA在固态薄膜状态下的发射光谱相对其二氯甲烷溶液的发射光谱明显变宽,而BNPA的固态薄膜并未发生光谱变宽现象。分别利用化合物BBPA和BNPA作为发光层材料,制备出了非掺杂的深蓝光电致发光器件。发光层为BBPA的电致发光器件的最大外量子效率和CIE色坐标分别为2.48%和(0.16,0.09);基于BNPA的电致发光器件的最大外量子效率为2.68%,CIE色坐标为(0.15,0.07)。所制备的这两种器件均表现出了较低的开启电压和良好的稳定性。     

Spatial coherence resonance induced by coloured noise and parameter diversity in a neuronal network

Spatial coherence resonance in a two-dimensional neuronal network induced by additive Gaussian coloured noise and parameter diversity is studied. We focus on the ability of additive Gaussian coloured noise and parameter diversity to extract a particular spatial frequency (wave number) of excitatory waves in the excitable medium of this network. We show that there exists an intermediate noise level of the coloured noise and a particular value of diversity, where a characteristic spatial frequency of the system comes forth. Hereby, it is verified that spatial coherence resonance occurs in the studied model. Furthermore, we show that the optimal noise intensity for spatial coherence resonance decays exponentially with respect to the noise correlation time. Some explanations of the observed nonlinear phenomena are also presented.