GaN肖特基紫外探测器分析

随着科学技术的不断进步,GaN基紫外材料在社会生产已经得到了广泛地应用,这项技术的充分发展,被认为是和发光二极管、激光器具有同样作用的一种器材。基于宽禁带半导体材料的GaN紫外探测器由于具有探测波长可调控性、工艺兼容性好、构造种类比较繁多等特点,现阶段它已经成为了同行界广泛研究的一个对象。GaN肖特基结构紫外探测器因为其具有很好的相应性能与很快的反应速度所以受到业界人士的如此青睐。笔者以肖特基结构探测器的不足之处作为着手点,研究并分析了这种新型的GaN肖特基结构紫外探测器。     

基于紫外差分吸收光谱的高温便携式 气体分析仪的设计

针对超低排放的烟气监测,研制了基于紫外差分吸收光谱技术的便携式高温烟气分析仪,阐述了分析仪的测量原理以及仪器的机械结构、光学、温控设计,采用不同浓度的SO2和NOX标准气体在不同环境条件下对该仪器进行测试,结果表明仪器的性能指标可达到污染源环保管理和环境污染应急监测的要求,具有良好的环境适应性。基于该仪器的硬件平台,未来通过扩展设计和应用开发升级也可应用于大气监测领域的走航监测。     

便携式紫外-可见光谱仪设计及关键技术研究

随着紫外光谱探测技术的广泛应用,低成本便携式紫外-可见光谱仪成为该领域的研究热点。本文首先依据交叉型Czerny-Turner结构设计了便携式紫外光谱仪光路结构。其次,针对性研究了紫外光谱仪的关键器件：紫外探测器和闪耀光栅。利用Lumogen荧光材料和蒸镀成膜法制作镀膜紫外增强CCD,并分析了荧光薄膜在CCD表面的位置对分辨率的影响;从理论上分析了闪耀光栅对于紫外波段的多级衍射效率的影响,确定了紫外光谱仪对于闪耀光栅的选择。最后,研制的便携式紫外-可见光谱仪样机的性能测试结果表明,200 nm~900 nm波段、25 μm狭缝宽度、600 lp/mm、300 nm闪耀光栅配置下分辨率整体小于1.5 nm,200 nm~300 nm紫外波段的光谱响应度提高到20%,实现了便携式紫外-可见光谱仪的设计要求。     

应用紫外·极紫外

介绍长春光机所八、九十年代在短波光学方面的某些研究工作     

新型便携式恒温槽的研制与应用

本文介绍了一种全新结构的便携式恒温槽，它与现有的恒温槽及干体炉相比，在300 ℃范围内具有使用方便，测量可靠性高等优点，可大大提高现场校准工作效率。     

GaN负电子亲和势光电阴极材料的生长研究

采用低压金属有机化学汽化淀积法在蓝宝石(0001)衬底上生长2~5μm厚度的P-AlxGa1-xN/GaN层(0     

海洋溢油管理标准化应用研究

海洋溢油管理工作的有效开展为海洋生态环境保护提供保障。标准化为实现海洋溢油管理工作的有效开展提供了技术支撑。本文阐述了标准化在海洋溢油管理工作中的作用,提出了推进海洋溢油管理标准化工作的策略和措施。     

浅谈便携式测振仪的应用

介绍便携式测振仪的使用,测点、参数的选择,根据测量数据正确做出诊断结果和处理意见,为设备状态监测和故障诊断提供科学依据。     

探索便携式坐标测量类设备软件验证方法

一般检定规程或校准规范只是对探索便携式坐标测量类仪器的综合误差或硬件指标进行检定、校准,而没有对其软件功能和算法的正确性进行验证和确认。本文依据实际工作中的管控要求,对软件验证和确认的重要性、难点进行分析,提出了一种简便、易于操作,适用于企业内部计量测试机构使用的基于算法比较和设备比较的软件验证方法,并通过激光跟踪仪软件验证实例,具体描述了验证过程和验证结果。     

气柱式便携封套野外封存应用验证

目的 验证气柱式便携封套在军事装备野外封存中的防护效果和勤务适应性,为军事装备野外封存防护探索解决方案.方法 基于高阻隔共挤复合膜材料和充气骨架自支撑结构,依据军事装备野外封存的防护需求和勤务要求,设计气柱式便携封套,并选择6个典型气候环境区的部队,进行为期1年的野外实装封存应用试验.结果 参与试验的6套气柱式便携封套中,有3套出现轻微破损,其余3套完好.设置在封套内的6套腐蚀挂片中,1套锈蚀严重,4套轻微锈蚀,1套无锈蚀.结论 气柱式便携封套防护性能较好,适合军事装备野外封存使用.建议进一步增强封套材料的耐磨性能,并解决野外用电问题.     

氮化镓肖特基结紫外探测器的异常特性测量

测量了CaN肖特基结紫外探测器在有、无光照下的I-V异常特性。分别用362nm和368nm光束对有源区进行横向扫描,得到了光照不同部位时探测器在无偏压、2V反向偏压下的电流。紫外光照到肖特基结压焊电极附近及透明电极边沿附近区域时,探测器在反向偏压下有较大增益,空间响应均匀性变差,在禁带内有两个增益响应峰波长——364nm和368nm。探测器在810nm光照射下,反向偏压下的光响应增益、持续光电导存在光淬灭现象。探测器紫外光照完后,俘获中心及表面陷阱所俘获的部分电荷在高反向偏置电压下老化可以通过隧穿或发射效应释放出来,经过高反向偏置电压老化完后的探测器在同一低反向偏置电压下暗电流比老化前的要小。测量结果为GaN器件的研制提供了参考数据。     

The improvement of GaN p-i-n UV sensor by 8-pair AlGaN/GaN superlattices structure

GaN with pairs of AlGaN/GaN superlattices (SLs) structure for p-i-n UV photo detector are fabricated on sapphire by metal organic chemical vapor deposition (MOCVD). For 8-pair AlGaN/GaN SLs not only eliminates cracking through this strain management, but it also significantly decreases the threading dislocation density by acting itself as an effective dislocation filter. The related structure has exhibited excellent film qualities such as enhanced crystallinity, lower specific contact resistance, lower etching pit density or mean roughness in the film. GaN p-i-n diode fabricated with 8-pair SLs, the dark current of device is reduced by two orders of magnitude than that without SLs structure at reverse bias of −3 V. Moreover, the peak UV responsivity is 0.12 A/W, which is higher than that without SLs is 0.07 A/W at 360 nm. The rejecting ratio is also by two orders of magnitude higher than that without SLs structure.     

Portable device for characterizing the angular response of UV spectroradiometers

This paper introduces a device that was developed to measure the angular response of UV spectroradiometers in the field. This device is designed to be used at the operating position of spectroradiometers; thus the derived angular response also includes any effects from imperfect leveling of the diffuser and corresponds to the actual operational angular response. The design and characterization of the device and the results from its application on 11 different spectroradiometers that operate at different European UV stations are presented. Various sources of uncertainties that were identified result in a combined uncertainty in determining the angular response, which ranges between approximately 1.5% and 10%, depending on the incidence angle and the characteristics of the diffuser. For the 11 instruments, the error in reporting the diffuse irradiance ranges between 2% and - 13%, assuming isotropic distribution of the downwelling radiances.     

抗蛋白吸附材料及其在海洋防污领域的应用前景

综述了抗蛋白吸附材料的种类及其抗蛋白吸附机制,分析了海生物污损发生过程中蛋白吸附的作用,展望了抗蛋白吸附材料在海洋防污领域的应用前景。     

Low-Noise and High-Detectivity GaN UV Photodiodes With a Low-Temperature AlN Cap Layer

Here, we present the characteristics of a novel GaN- based ultraviolet (UV) photodiode (PD) with a low-temperature (LT) AIN cap layer. The dark leakage current for the PD with the LT-AIN cap layer was shown to be about four orders of magnitude smaller than that for the conventional PDs. It was found that we could achieve larger UV to visible rejection ratio by inserting an LT-AIN cap layer. It was also found that we could improve minimum noise equivalent power and maximum normalized detectivity of the PD by inserting an LT-AIN cap layer.     

Low-Noise and High-Detectivity GaN-Based UV Photodiode With a Semi-Insulating Mg-Doped GaN Cap Layer

GaN-based ultraviolet photodiodes with a semi-insulating Mg-doped GaN cap layer were fabricated and characterized. Dark leakage current of the aforementioned photodiodes was much smaller than that of the conventional ones without the Mg-doped GaN cap layer due to a thicker and higher potential barrier and less amounts of interface states after inserting the Mg-doped GaN cap layer. The ultraviolet to visible rejection ratio is 3.44 x 10³ by inserting a semi-insulating Mg-doped GaN cap layer with a -IV applied bias. In this study, we also discuss the noise characteristics. It was found that minimum noise equivalent power and maximum detectivity of our photodiode were 1.2 x 10^-12 W and 9.34 x 10¹¹ cmHz^0.5 W^-1, respectively.