Dual-band infrared detectors

IntroductionMulticolor capabilities are highly desirable foradvance infrared(IR) systems.Systems that gatherdata in separate IR spectral bands can discriminateboth absolute temperature and unique signatures ofobjects in the scene.By providing this new dimensionof contrast,multiband detection also enables ad-vanced color processing algorithms to further im-prove sensitivity above that of single- color devices.This is extremely important for the process of identi-fying temperature difference b…     

中波-长波双色量子阱红外探测器

采用n型掺杂的AlGaAs/GaAs和AlGaAs/InGaA多量子阱材料,基于MOCVD外延生长技术,利用成熟的GaAs集成电路加工工艺,设计并制作了不同结构的中波-长波双色量子阱红外探测器(QWIP)器件,器件采用正面入射二维光栅耦合,光栅周期设计为4μm,宽度2μm;对制作的500μm×500μm大面积双色QWIP单元器件暗电流、响应光谱、探测率进行了测试和分析。在-3V偏压、77K温度和300K背景温度下长波(LWIR)和中波(MWIR)QWIP的暗电流密度分别为0.6、0.02mA/cm2;-3V偏压、80K温度下MWIR和LWIR QWIP的响应光谱峰值波长分别为5.2、7.8μm;在2V偏压、65K温度下,LWIR和MWIR QWIP的峰值探测率分别为1.4×1011、6×1010cm.Hz1/2/W。     

GaAs／AlGaAs量子阱红外探测器特性非对称性分析

在分子束外处生长量子阱材料过程中,分析了在不同的GaAs/AlGaAs异质结生长次序中Ga的解吸附速率不同和量子阱中掺杂的扩散造成量子阱结构的不对称,讨论了GaAs/AlGaAs最子红外探测器的性能参数相对于正负偏压的不对称性,并与金属有机化合物汽相沉淀法生长的最子阱材料和相应器件进行了比较,发现,采用分子束外延方法生长器件的不对称性更明显。     

甚长波量子阱红外探测器光耦合性能

从实验、测试和计算结果出发,运用有限时域差分法(FDTD)和传统的模式扩展(MEM)理论,研究甚长波量子阱红外探测器(QWIP)几种衍射光耦合的表面近场效应和光耦合效率,重点考察QWIP 45°面边耦合、光栅耦合QWIP结构、光栅尺寸、工艺条件的变化对QWIP相关性能的影响.实验与计算结果证明,合理地设计二维光栅,进行甚长波QWIP光耦合,可以获得有效的光耦合效果.     

面向工程化应用的量子阱红外探测材料制备研究

为了得到高性能的量子阱红外探测材料,本文通过建立系统的材料设计、材料生长及材料表征体系,对面向工程化应用要求的单色以及双色红外探测的量子阱材料制备技术进行了较深入探索,并得到了相应部分器件的测试结果,实践证明,通过工艺与控制过程优化,量子阱红外探测材料的制备可实现高的可控性和稳定性。     

面向QWIP焦平面阵列的快照模式低温读出电路

介绍了应用于GaAs/AlGaAs量子阱红外焦平面阵列的快照模式的低温读出电路的设计方法与测试结果。读出电路采用CTIA作为输入电路,提出在单元输入电路中引入内建电注入器件进行读出电路封装前测试。对读出电路的低温和低功耗进行了优化设计。基于该方法采用0.35um CMOS工艺设计制造了阵列尺寸为128×128的读出电路实验芯片。测试结果表明,读出电路能够在77K的温度下正常工作,功耗为35mW。该读出电路象元级的电荷容量为2.57×106电子,跨导系数为1.4×107Ω。分析表明,在3.3V电源电压下,当输出速率为10MHz时,实验芯片的非均匀性小于5%。     

Numerical analysis of SiGeSn/GeSn interband quantum well infrared photodetector

In this paper, detailed theoretical investigation on the frequency response and responsivity of a strain balanced SiGeSn/GeSn quantum well infrared photodetector (QWIP) is made. Rate equation and continuity equation in the well are solved simultaneously to obtain photo generated current. Quantum mechanical carrier transport like carrier capture in QW, escape of carrier from the well due to thermionic emission and tunneling are considered in this calculation. Impact of Sn composition in the GeSn well on the frequency response, bandwidth and responsivity are studied. Results show that Sn concentration in the GeSn active layer and applied bias have important role on the performance of the device. Significant bandwidth is obtained at low reverse bias voltage, e.g., 200?GHz is obtained at 0.28?V bias for a single Ge_0.83Sn_0.17 layer. Whereas, the maximum responsivity is of 8.6?mA/W at 0.5?V bias for the same structure. However, this can be enhanced by using MQW structure.     

量子阱红外探测器最新进展

量子阱红外探测器(QWIP)自从20世纪80年代被验证后,得到了广泛积极的研究。基于Ⅲ-Ⅴ材料体系、器件工艺的成熟和自身的稳定性、响应带宽窄等特有的优势,QWIP成为对低成本、大面阵、双(多)色高精度探测有综合要求的第三代红外焦平面阵列(FPA)的重要发展方向。本文主要总结了国际QWIP器件的最新发展动态,并展望了其发展趋势。     

QWIP or other alternative for third generation infrared systems

Choosing the right detector technology for third generation thermal imaging systems is directly derived from the requirements of these new generation infrared imaging systems.

It is now evident that third generation thermal imager will still need the higher resolution capabilities as well as capabilities in multispectral detection and polarization sensitivity. Four technologies candidates are analyzed; the field-proved HgCdTe (MCT), uncooled microbolometer technology, antimonide based materials and quantum well infrared photodetectors (QWIP). Taking into account the risks, maturity and technologies barrier of each technology, we claim that for non-strategic applications (not low background conditions), QWIP technology is the most favorite. The ternary and superlattice antimonide based materials group seems to be theoretically the best alternative, but are not recommended due to its immaturity and the high risk involved in this technology (passivation, doping control, etc.). We anticipate large penetration of the uncooled detectors to the low-end and medium-end market. The HgCdTe will still be in progress due to the inertia of the large funding and the strategic importance of this detectors technology.     

QUANTUM MECHANICAL MODEL AND SIMULATION OF GaAs／AlGaAs QUANTUM WELL INFRARED PHOTODETECTOR—Ⅱ ELECTRICAL ASPECTS

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