Photodetector Nonlinearities Due to Voltage-Dependent Responsivity

A newly quantified photodiode nonlinearity is derived from a previously known bias voltage-dependent responsivity. For an InGaAs p-i-n photodiode, measured harmonic distortion is shown to be dominated by this derived nonlinearity mechanism. It is also shown that electron ionization in the depletion region of the photodiode is the source of the voltage-dependent responsivity.      

Responses to Incongruent Verbal and Nonverbal Emotional Cues

An alternate forms test was constructed with each test consisting of 40 20-second segments of tape. Each segment had built into it a conflict in degree of stress between the verbal (V) mode and the nonverbal (NV) mode, in that when V stress was high, NV stress was low, and vice versa. Ss rated the combined audio-video channels on a 9-point scale ranging from calm to stressed. Each S's ratings were correlated with V and NV criteria established by pretest judges as well as with a maximum stress criterion. Results indicated that Ss differed reliably in their preferences for V and NV cues. A difference in general sensitivity to all available cues is suggested by the finding that NV responders were able to detect stress in the V mode also, while the V responders showed little ability to respond to NV cues. A third group also correlated with the maximum stress criterion but had no V or NV mode preference.     

高响应度GaN紫外探测器

采用MOCVD方法,在蓝宝石衬底上以低温GaN为缓冲层生长了GaN外延层。以上述材料制备了金属-半导体-金属(M-S-M)光导型GaN探测器。该探测器的光谱响应表明:器件在330～360nm内有高的灵敏度,并且在360nm附近有陡峭的截止边,对可见光和近红外光几乎没有响应,在5V偏压下358nm处峰值响应度高达1200A/W。研究了光从探测器的正、背面入射时对响应度的影响,并讨论了其原因。     

Responsivity and lifetime of resonant-cavity-enhanced HgCdTe detectors

Resonant-cavity-enhanced HgCdTe structures have been grown by molecular beam epitaxy, and photoconductors have been modelled and fabricated based on these structures. Responsivity has been measured and shows a peak responsivity of 8 × 10⁴ V/W for a 50 × 50 μm² photoconductor at a temperature of 200 K. The measured responsivity shows some agreement with the modelled responsivity across the mid-wave infrared window (3–5 μm). The measured responsivity is limited by surface recombination, which limits the effective lifetime to ≈15 ns. The optical cut-off of the detector varies with temperature as modelled from 5.1 μm at 80 K to 4.4 μm at 250 K. There is strong agreement between modelled peak responsivity and measured peak responsivity with varying temperature from 80 to 300 K.     

InGaAs短波红外探测器的偏振响应特性分析

在偏振成像和激光功率测量技术领域,凡涉及偏振光的定量测量,都会由于光束的偏振态对探测器的影响而产生显著的误差.这种现象主要是由于许多类型的光探测器存在偏振敏感响应引起的.本文对光电探测器的偏振响应进行了分析,推导了光电探测器偏振相关损耗的斯托克斯模型.分析了SiNx钝化膜对InGaAs探测器偏振响应的影响.结果表明,无SiNx钝化膜时,随着入射角度的增加,偏振响应损耗明显增加,而随着波长的增加,偏振响应损耗明显降低;采用SiNx钝化膜时,随着波长的增加,偏振响应损耗先减小后增加.由于设计的SiNx薄膜的增透中心波长为1550nm,1310nm波长处的偏振响应损耗大于1550nm处的偏振响应损耗.     

Extended Spectral Responsivity Aids Artwork investigations

CEDIP Infrared Systems has published technical data establishing the considerable utility of its JADE SWlR IR camera system for the investigation and visualisation of sub-surface preliminary artwork on paintings.     

探测器波段响应率及其测试定标法

描述了碲镉汞红外探测器相对光谱分布Ｇ（λ）和波段响应率Δλ的测试计算方法，以及其在１０５Ｋ温度下工作时，其中的一些定标问题，给出了１０５Ｋ温度下工作，空间应用的碲镉汞光导红外探测器有关测试方法、设备及测试结果，并给出了相应的测试误差。     

高响应度InGaAs PIN光电探测器的研制

分析了影响探测器响应度的各因素,在此基础上设计了InGaAs/InP PIN探测器的外延材料结构并优化了增透膜厚度和p-InP区欧姆接触电极图形的设计,以达到提高响应度的目的。采用MOCVD技术和闭管扩散等工艺制备了器件并测量了其响应度。结果显示,器件的光谱响应范围为1000~1600nm,在1500nm激光的辐照下,5V反向偏压时器件的响应度可达0.95A/W以上。     

高响应度InGaAs PIN光电探测器的研制

分析了影响探测器响应度的各因素，在此基础上设计了InGaAs/InP PIN探测器的外延材料结构并优化了增透膜厚度和p-InP区欧姆接触电极图形的设计，以达到提高响应度的目的。采用MOCVD技术和闭管扩散等工艺制备了器件并测量了其响应度。结果显示，器件的光谱响应范围为1000-1600nm，在1500nm激光的辐照下，5V反向偏压时器件的响应度可达0.95A/W以上。     

基于塞贝克效应的高响应度太赫兹探测器的研究

针对微弱太赫兹激光功率的测试需求,本文研究一种可以提高太赫兹探测器响应度的方法.采用反射式太赫兹时域光谱分析仪测试太赫兹激光吸收材料的吸收率,选择吸收率高的材料作为太赫兹激光的吸收材料;使用直流磁控溅射技术在太赫兹激光吸收材料底部均匀的镀上一层金薄膜;利用具有高导热率和高粘接强度的固化液体硅胶把太赫兹激光吸收材料与热电堆的热端粘接在一起,并把热电堆的冷端与热沉紧密粘贴.理论分析和实验结果表明此方法有效提高了热电堆的热电转换率和吸收材料对太赫兹激光的吸收率,从而使太赫兹探测器的响应度提升了7.9%.因此,本文研制的太赫兹探测器在0.1 THz~10 THz范围内,能够实现微瓦量级太赫兹激光功率的测试.     

用傅里叶光谱仪测量探测器光谱响应方法的研究

详细介绍了一种新颖的测量探测器光谱响应的方法。与过去的方法相比，它具有灵敏度高、测量速度快、测量精度高、操作方便等优点。该方法以傅里叶光谱仪为主要测量设备，配合相应的测量软件，非常方便适用。本文主要介绍它的原理和部分测量结果。     

硅全耗尽背照式光电二极管的光谱响应

建立了一个预测硅全耗尽背照式光电二极管响应率的解析模型.分析了所加反偏压与光谱响应之间的关系,解出了硅全耗尽背照式光电二极管的响应率和器件各参数之间的关系,并根据选定参数值计算出了给定外加偏压下400～1 100 nm范围的光谱响应曲线,预测探测器光谱响应峰值在1μm,峰值响应率达到0.72 A/W.实测结果表明:器件峰值响应与预测一致,反偏压对响应率的影响与预测相同,即响应率随着反偏压的升高而增大.并且在各种反偏压下的光谱响应曲线形状与预测基本吻合,证明了建立的模型可以正确地预测器件性能.     

红外探测器相对光谱响应率的自动测试

介绍红外探测器相对光谱响应率自动测试的实施方法。利用锁相放大器追踪测量信号,微机自动扫描、采集和处理数据。给出了整个测试过程的流程图,对影响测试准确度的因素,如光源、参考探测器及其他干扰进行了较详细的阐述。并介绍提高测试准确度的措施,给出测量实例及误差分析。测试结果表明,此装置已能满足红外测试标准所要求的精度。     

高响应度GaN肖特基势垒紫外探测器的性能与分析

制作了反向饱和电流为5.5×10-14 A/cm2,势垒高度为1.18eV的GaN肖特基势垒紫外探测器.测量了探测器分别在零偏压及反向偏压下的光谱响应度,响应度随反向偏压无显著变化,零偏压下峰值响应度在波长358.2nm处达到了0.214A/W.利用波长359nm光束横向扫描探测器的光敏面,测量了探测器在不同偏压下的空间响应均匀性,相应偏压下的光响应在光敏面中央范围内响应幅值变化不超过0.6%.光子能量在禁带边沿附近的光束照射下,GaN肖特基势垒紫外探测器存在势垒高度显著降低现象,这种现象在肖特基透明电极边沿及其压焊电极附近表现得更为突出.探测器在368和810nm波长光一起照射时的开路电压比只有368nm光照射时的开路电压大,而零偏压下两者的光电流近似相等.利用这种开路电压变化效应估算了探测器在368nm光照射下,表面被俘获空穴的面密度变化量约为8.4×1010 cm-2.     

HEMT太赫兹探测器响应度和NEP的检测与分析

在0.8～1.1 THz内,对AlGaN/GaN高电子迁移率晶体管(HEMT)太赫兹探测器的响应度和噪声等效功率进行了具体测试和分析。在太赫兹波辐射下,HEMT太赫兹探测器源漏端产生能被栅压灵敏调控的直流光电流。该型探测器在300 K和77 K下的电流响应度分别为83 mA/W和4.1 A/W,电压响应度分别为4 kV/W和50 kV/W,噪声等效功率分别达到22 pW/Hz0.5和1 pW/Hz0.5。采用两种较为典型的测量方法,通过对实验结果的比较,确定了影响该类型探测器的响应度和噪声等效功率的主要因素,并提出了增强响应度和降低噪声等效功率的具体措施。     

Using Bulk Heterojunctions and Selective Electron Trapping to Enhance the Responsivity of Perovskite–Graphene Photodetectors

Graphene field effect transistor sensitized by a layer of semiconductor (sensitizer/GFET) is a device structure that is investigated extensively for ultrasensitive photodetection. Among others, organometallic perovskite semiconductor sensitizer has the advantages of long carrier lifetime and solution processable. A further step to improve the responsivity is to design a structure that can promote electron–hole separation and selective carrier trapping in the sensitizer. Here, the use of a hybrid perovskite–organic bulk heterojunction (BHJ) as the light sensitizer to achieve this goal is demonstrated. Our spectroscopy and device measurements show that the CH₃NH₃PbI₃–PCBM BHJ/GFET device has improved charge separation yield and carrier lifetime as compared to a reference device with a CH₃NH₃PbI₃ sensitizer only. The key to these enhancement is the presence of [6,6]‐phenyl‐C₆₁‐butyric acid methyl ester (PCBM), which acts as charge separation and electron trapping sites, resulting in a 30‐fold increase in the photoresponsivity. This work shows that the use of a small amount of electron or hole acceptors in the sensitizer layer can be an effective strategy for improving and tuning the photoresponsivity of sensitizer/GFET photodetectors.     

高响应度GaN肖特基势垒紫外探测器的性能与分析

制作了反向饱和电流为5.5×10-14 A/cm2,势垒高度为1.18eV的GaN肖特基势垒紫外探测器.测量了探测器分别在零偏压及反向偏压下的光谱响应度,响应度随反向偏压无显著变化,零偏压下峰值响应度在波长358.2nm处达到了0.214A/W.利用波长359nm光束横向扫描探测器的光敏面,测量了探测器在不同偏压下的空间响应均匀性,相应偏压下的光响应在光敏面中央范围内响应幅值变化不超过0.6%.光子能量在禁带边沿附近的光束照射下,GaN肖特基势垒紫外探测器存在势垒高度显著降低现象,这种现象在肖特基透明电极边沿及其压焊电极附近表现得更为突出.探测器在368和810nm波长光一起照射时的开路电压比只有368nm光照射时的开路电压大,而零偏压下两者的光电流近似相等.利用这种开路电压变化效应估算了探测器在368nm光照射下,表面被俘获空穴的面密度变化量约为8.4×1010 cm-2.     

结构和工艺对碲镉汞光导探测器响应率的影响

分析了探测器表面复合和扫出效应对光激发非平衡栽流子寿命和响应率的影响。并进行了实例数字计算,提出了表面和扫出的影响是目前8～14μm碲镉汞光导探测器在工艺和结构上必须予以重视的问题。     

红外探测器光谱响应自动测试

介绍红外探测器相对光谱自动测试方法。通过软件编程实现功能选择。利用双路锁相放大器跟踪测量信号，微机自动扫描、采集和处理数据，实现了红外探测器光谱响应的自动测试。文中给出了整个测试过程的流程图。我们对影响测试精度的因素，如在ＨＲ６４０光谱仪的入射、出射狭缝前后和其它配置上采取了一些改进措施，使本装置具有特色，提高了测试精度。文中给出测试实例。测试结果表明，此装置已能满足红外探测器测试标准所要求的精度。