日盲型AlGaN PIN紫外探测器的研制

采用MOCVD方法在双面抛光的(0001)蓝宝石衬底上生长了高铝组分AlGaN材料,研制出日盲型AlGaN PIN紫外探测器.详细介绍了该器件的结构设计和制作工艺,并对该器件进行了光电性能测试.测试结果表明:器件的正向开启电压约为4.5 V,反向击穿电压大于20 V;常温下(300 K),该器件在3 V反向偏压下的暗电流约为50 pA,在零偏压下270 nm处峰值响应度达到0.12 A/W,长波截止波长小于285 nm.     

AIInGaN／GaN PIN紫外光电探测器的研制

用AlInGaN四元合金代替AlGaN作为PIN探测器的有源层,研制出AlInGaNPIN紫外探测器。详细介绍了该器件的结构设计和制作工艺,并对器件进行了光电性能测试。测试结果表明,器件的正向开启电压约为1．5V,反向击穿电压大于40V;室温-5V偏压下,暗电流为33pA,350nm处峰值响应度为0．163A／W,量子效率为58％。     

AlInGaN/GaN PIN紫外光电探测器的研制

用AlInGaN四元合金代替AlGaN作为PIN探测器的有源层,研制出AlInGaNPIN紫外探测器.详细介绍了该器件的结构设计和制作工艺,并对器件进行了光电性能测试.测试结果表明,器件的正向开启电压约为1.5 V,反向击穿电压大于40 V;室温-5 V偏压下,暗电流为33 pA,350 nm处峰值响应度为0.163 A/W,量子效率为58%.     

AlGaN MSM结构日盲型紫外探测器

采用低压-金属有机化学气相沉积(MOCVD)法在(0001)方向的AlN/蓝宝石模板上生长得到Al组分为40%的AlGaN材料,设计并制作了MSM型AlGaN日盲紫外探测器。通过HRXRD,SEM,AFM对AlGaN材料进行了表征,结果表明:该材料为六方相结构,且应变程度很小,粗糙度(RMS)为1.32 nm。通过测试器件在230³20 nm之间、在不同偏压下的光谱响应曲线,发现器件的截止波长在285 nm附近,截止边很陡峭;器件的峰值响应波长为275 nm;在7 V偏压下,器件峰值响应度达到最大2.8 mA/W;零偏压下,器件的暗电流1×10-13A,器件的暗电流很小。     

基于日盲型AlGaN的紫外相机设计

在"日盲段"240～290 nm进行窄波段探测,具有背景干扰小的优势。相比于传统紫外探测器必须协同窄带滤光片工作,AlGaN具有固有窄波段控制和无需制冷两大优点。介绍了基于日盲型AlGaN焦平面器件的紫外相机的软、硬件设计。紫外相机由紫外透射式光学系统,日盲型AlGaN器件,偏置电路及驱动电路,低噪声前放、数据处理及传输单元构成,核心器件AlGaN采用背照式PIN阵列通过铟柱倒焊于硅基电容反馈跨导放大器(CTIA)读出电路的结构。紫外相机的设计指标为:光学口径80 mm,焦距130 mm,像元尺寸50μm,瞬时视场0.4 mrad,总视场3°,积分时间可控,帧率最高可达100帧/s。经初步室内测试,效果良好,对发展日盲型面阵AlGaN应用平台做出了有意义的探索和研究。     

AlGaN基p-i-n型日盲紫外探测器材料的研制

采用金属有机气相外延(MOCVD)方法在(0001)面蓝宝石衬底上生长了AlN和高铝组分AlGaN材料。通过优化AlN和AlGaN材料的生长温度、生长压力和Ⅴ族元素/Ⅲ族元素物质的量比(nⅤ/Ⅲ)等工艺条件,得到了高质量的AlN和高铝组分AlGaN材料。AlN材料X射线双晶衍射ω(002)半宽为74 arcsec,透射光谱测试带边峰位于205 nm,带边陡峭;Al组分为45%的AlGaN材料X射线双晶衍射ω(002)半宽为223 arcsec,透射光谱测试带边峰位于272 nm,带边陡峭。采用此外延工艺方法生长了AlGaN基p-i-n型日盲紫外探测器材料并进行了器件工艺流片,研制出AlGaN基p-i-n型日盲紫外探测器,响应峰值波长为262 nm,在零偏压下的峰值响应度达到0.117 A/W。     

结合AlGaN和PVDF的新型日盲紫外探测器的研究

制作了一种新型的结合了AlGaN材料结构和Poly（vinylidene fluoride）（PVDF）热释电材料的日盲紫外探测器。当紫外光从AlGaN一侧背照射至器件上时,测量PVDF两端的热释电响应光谱,测得峰值响应在入射光波长为260 nm处,响应电压高达129.6 mV（此时辐射功率为39.8 nW）。器件响应机理为:紫外光被i-Al0.35Ga0.65层吸收,产生光生载流子并复合生热,热量通过AlGaN材料传导给PVDF结构的电极,温度升高,PVDF对温度变化产生响应。为了进一步验证,制作了对比器件,即在AlGaN结构和PVDF结构之间加了一层多孔SiO2隔热层,测得的响应光谱中有两个峰值,一个在260 nm,另外一个在300 nm。与参考器件相比,在260 nm处的响应电压大大减小,说明了利用热效应探测的可行性。另外,测量了不同频率下的器件响应并对其进行理论拟合,深入研究300 nm处的响应机理。     

AlGaN/GaN型气敏传感器对于CO的响应研究

研究了基于AlGaN/GaN型结构的气敏传感器对于C0的传感性.制备出AlGaN/GaN型气敏传感器器件,并测试得到了器件在50℃时对于不同浓度(1%,9000,8000,5000和1000ppm)的C0的响应情况;测试并分析了1%CO在50和100℃下响应度的差异,计算了通人1%CO前后器件的肖特基势垒高度的变化和灵敏度随电压的分布关系.结果表明,器件的灵敏度强烈依赖于器件的工作温度和通入的气体浓度,随着温度和浓度的增加,器件的灵敏度呈单调增加,器件在100℃空气气氛中表现出了良好恢复性能.     

AlGaN/GaN型气敏传感器对于C0的响应研究

研究了基于AlGaN/GaN型结构的气敏传感器对于C0的传感性.制备出AlGaN/GaN型气敏传感器器件,并测试得到了器件在50℃时对于不同浓度(1%,9000,8000,5000和1000ppm)的C0的响应情况;测试并分析了1%CO在50和100℃下响应度的差异,计算了通人1%CO前后器件的肖特基势垒高度的变化和灵敏度随电压的分布关系.结果表明,器件的灵敏度强烈依赖于器件的工作温度和通入的气体浓度,随着温度和浓度的增加,器件的灵敏度呈单调增加,器件在100℃空气气氛中表现出了良好恢复性能.     

AlGaN/GaN型气敏传感器对于CO的响应研究

研究了基于AlGaN/GaN型结构的气敏传感器对于CO的传感性.制备出AlGaN/GaN型气敏传感器器件,并测试得到了器件在50℃时对于不同浓度（1%,9000,8000,5000和1000ppm）的CO的响应情况;测试并分析了1%CO在50和100℃下响应度的差异,计算了通入1%CO前后器件的肖特基势垒高度的变化和灵敏度随电压的分布关系.结果表明,器件的灵敏度强烈依赖于器件的工作温度和通入的气体浓度,随着温度和浓度的增加,器件的灵敏度呈单调增加,器件在100℃空气气氛中表现出了良好恢复性能.     

InGaN/GaN MQW p–n junction photodetectors

InGaN/GaN multiquantum well (MQW) p–n junction photodetectors with semi-transparent Ni/Au electrodes were fabricated and characterized. It was found that the fabricated InGaN/GaN MQW p–n junction photodetectors exhibit a 20 V breakdown voltage and a 3.5 V forward 20 mA turn on voltage. It was also found that the photocurrent to dark current contrast ratio is higher than 10⁵ when a 0.4 V reverse bias was applied to the InGaN/GaN MQW p–n junction photodetectors. Furthermore, it was found that the maximum responsivity was 1.28 and 1.76 A/W with a 0.1 and 3 V applied reverse bias, respectively.     

Pt/CdS Schottky势垒紫外探测器的研制

介绍了Pt/CdS金属半导体接触Schottky势垒形成及In/CdS的欧姆接触工艺研究,由此制成了紫外探测器.测试了探测器的Ⅰ-Ⅴ特性,零偏下的光谱响应和器件的频率响应.观察了器件的反偏响应情况.获得的探测器在λ=440am处加两伏反偏时的响应率为0.17A/W,内量子效率最大可达64%.     

High-speed Ga0.47In0.53As MISIMphotodetectors with dielectric-assisted Schottky barriers

A technique is described for fabricating high-speed metal-insulator-semiconductor-insulator-metal (MISIM) photodetectors for high-speed fiber-optic systems. These devices make use of a Langmuir-Blodgett film enhanced Schottky barrier to achieve broadband linear response to 13 GHz at low bias voltage (5 V) with ~0.9 A/W external responsivity, 15 V breakdown voltage, and ~2 μA dark current. A gain of about 2 and a 5% tail in the temporal response are analyzed. The needed bias and the device processing are compatible with those for integrated receivers     

Nitride-based p-i-n bandpass photodetectors

Nitride-based p-i-n bandpass photodetectors with semitransparent Ni-Au electrodes were successfully fabricated and characterized. The photodetectors exhibit a 20-V breakdown voltage and a small dark current of 40 pA at 4-V reverse bias. It was found that spectral responsivity shows a narrow bandpass characteristics from 337 to 365 nm. Moreover, the peak responsivity was estimated to be 0.13 A/W at 354 nm, corresponding to a quantum efficiency of 44%. The relatively high response at shorter wavelength is due to the unoptimized thickness of p-Al/sub 0.1/Ga/sub 0.9/N absorption layer. At low frequency, the noise of the photodetector is dominant by the 1/f-type noise. For our 330/spl times/330 /spl mu/m/sup 2/ device, given a bias of -3.18 V, the corresponding noise equivalent power and normalized detectivity D/sup */ are calculated to be 5.6/spl times/10/sup -12/ W and 3.34/spl times/10/sup 11/ cmHz/sup 0.5/ W/sup -1/, respectively.     

AlGaN日盲紫外雪崩光电探测器暗电流研究

为了提高AlGaN日盲紫外雪崩探测器的信噪比,降低暗电流,研制高性能日盲紫外探测器,针对AlGaN日盲紫外雪崩探测器暗电流机制进行了深入研究。首先对传统p-i-n-i-n结构雪崩探测器进行了初步研究,分别设计了GaN和AlGaN的两种雪崩探测器模型,分析了其不同暗电流特性,得到的模拟暗电流特性曲线与实验吻合。在此基础上,针对日盲紫外波段高Al组分AlGaN雪崩探测器,重点分析研究了不同异质界面的负极化电荷、p型有效掺杂以及温度等因素对暗电流的影响。在AlGaN日盲紫外雪崩探测器研究中得到的近零偏工作暗电流为2.510-13 A,在反向138 V左右发生雪崩击穿,雪崩开启电流为18.3 nA左右,击穿电压温度系数约为0.05 V/K,与实验及文献测试结果吻合。     

In2Ge2O7薄膜制备及其紫外光敏特性研究

以In2O3和GeO2为原料,采用碳还原法制备了In2Ge2O7多晶薄膜,利用XRD和SEM对薄膜的结构和形貌进行了表征。对基于In2Ge2O7薄膜的金属-半导体-金属(MSM)紫外探测器进行了紫外光电导特性测量,结果显示:在波长为250nm的紫外光照射下,在5V偏压下,器件的光电流为727μA(暗电流为12μA),光响应度达到262.9A.W-1,光响应上升时间约为67s,下降时间约为15s。分析认为较长的响应时间是由于内部的缺陷与位错造成的。初步研究结果表明:In2Ge2O7薄膜可以作为一种良好的日盲紫外探测材料。     

p-GaN/Al0.35Ga0.65N/GaN应变量子阱肖特基紫外探测器

报道了p-GaN/Al0.35Ga0.65N/GaN应变量子阱结构的肖特基紫外探测器的制备及性能.器件的测试结果表明,在p-GaN/Al0.35Ga0.65N/GaN双异质结中强烈的压电极化和Stark效应共同作用下使得器件在正偏和反偏时的响应光谱都向短波方向移动了10nm.零偏下器件在280nm时的峰值响应为0.022A/W,在反向偏压为1V时,峰值响应增加到0.19A/W,接近理论值.在正向偏压下器件则呈平带状态,并在283和355nm处分别出现了两个小峰.在考虑极化的情况下,通过器件中载流子浓度分布的变化解释了器件在不同偏压下的响应特性,发现p-GaN/Al0.35Ga0.65N/GaN中的极化效应对器件的响应特性影响很大,通过改变偏压和适当的优化设计可以使探测器在紫外波段进行选择性吸收.     

Visible blind p-π-n-n ultraviolet photodetectors based on 4H-SiC homoepilayers

p⁺-π-n⁻-n⁺ ultraviolet photodetectors based on 4H-SiC homoepilayers have been presented. The growth of the 4H-SiC homoepilayers was carried out in a LPCVD system. The size of the active area of the photodetectors was 300×300 μm². The dark and illuminated I-V characteristics had been measured at reverse biases form 0 to 20 V at room temperature, and the illuminated current was at least two orders of magnitude than that of dark current below 13 V bias. The peak value zones of the photoresponse were located at 280-310 nm at different reverse biases, and the peak value located at 300 nm was 100 times greater than the cut-off response value in 380 nm at a bias of 10 V, which showed the device had good visible blind performance. A small red-shift about 5 nm on the peak responsivity occurred when reverse bias increased from 5 to 15 V.     

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。     

The Ring-Shaped CMOS-Based Phototransistor With High Responsivity for the UV/Blue Spectral Range

The ring-shaped phototransistor with a floating bulk enclosed by a ring-shaped photodiode is proposed to enhance the responsivity for the ultraviolet/blue spectral range. The P-channel metal–oxide–semiconductor field-effect transistor and N-channel metal–oxide–semiconductor field-effect transistor phototransistors were manufactured using a standard 0.35-$mu hbox{m}$ complimentary metal–oxide–semiconductor (CMOS) technology. When the phototransistors were illuminated with 400-nm light, the measurement results for 3-V bias demonstrated a responsivity higher than 1500 A/W, which is also superior to that of other reported photodetectors manufactured using a standard CMOS technology. Even for very small bias voltages such as 0.1 V, the phototransistor can exhibit a responsivity of 17.9 A/W.