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1.
MODIFICATION OF ABSORPTION SPECTRUM OF GaAs/AlGaAs QUANTUM WELL INFRARED PHOTODETECTOR BY POSTGROWTH ADJUSTMENT
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IntroductionSince 1980s,the infrared detector based on inter-subband transitions in quantum well(QW)systems,called the quantum well infrared photoconductor(QWIP),has been studied and developed extensivelyand successfully[1].Quantumwell intermixing(QWI)tec… 相似文献
2.
AlGaAs/GaAs量子阱探测器的吸收光谱研究 总被引:1,自引:0,他引:1
从定态Schrodinger方程出发,研究了不同Al组分和不同温度对宽量子阱红外探测器吸收光谱的影响。当体系的费米能级固定后,发现量子阱基态束缚能随着A1组分增长而变大,且相应的吸收光谱峰值趋于短波。环境温度对A1GaAs/GaAs量子阱红外探测器的响应光谱影响不大。通过理论计算定量给出了A1GaAs/GaAs量子阱红外探测器吸收光谱随量子阱阱宽、Al组分和温度变化的规律。 相似文献
3.
对GaAs/AlGaAs多量子阱红外探测器外延材料进行了光致荧光谱(PL)测量,结合理论计算,由材料吸收峰位置得到势垒高度以及势阱基态位置,并由此推算出相应的红外探测响应波长。推算结果与器件光电流实验值的对比表明,由光致荧光谱(PL)测量结果计算得到的响应波长与实际器件的响应波长有良好的一致性。 相似文献
4.
Fu Y Willander M 《红外与毫米波学报》2002,21(5):321-326
IntroductionInfrareddetectortechniquehasbeenakeyfactorinthedevelopmentoftheinfraredtechnologyformorethan 4 0 years .Since 1970 ,semiconductorslikeInSbandHgCdTehavebeentheprincipalmaterialsforvariousinfrareddetectorapplications .Theformatoftheinfrareddetectormotivatedbysmartthermalimagingsystemchangedfromsingleelementdevicetofocalplanarrays(FPAs)inthemiddleof 80’s [1].Today’stechnologyofinfrareddetectorconcentrateslargelyonfocalplanarrays ,expeciallyforsensitive ,homogeneousandlargeformatscaledevices .HgCdTe... 相似文献
5.
对用MBE生长的GaAs/A lGaAs量子阱材料进行了衬底剥离,在此基础上制备了单元器件并测量了器件的黑体响应率以及光电流响应.实验解决了衬底剥离及器件制备中的工艺问题,研究了衬底剥离对材料及器件性能的影响以及用这种方法制备器件的可行性.结果表明选择腐蚀法是一种有效的衬底剥离方法,用这种方法得到的多量子阱薄膜材料仍具有较好的红外探测性能,为进一步实验提供了依据. 相似文献
6.
时域有限差分法模拟量子阱红外探测器光栅的光耦合 总被引:4,自引:2,他引:2
由于量子选择定则的限制,对于量子阱红外探测器(QWIP),必须利用衍射光栅增强其光学偶合效率,本文给出了一种基于时域有限差分法(FDTD)的数值方法,计算制备在QWIP器件上的金属光栅的衍射效应,模拟计算的结罘表明,FDTD方法是解析这种复杂结构内电磁场问题的有效手段.可以计算QWIP器件内各点电磁场所有分量的详细分布,进而可以估算衍射光栅的偶合效率,以及优化QWIP结构设计。 相似文献
7.
研究了Cu/SiO_2逐层沉积增强的无杂质空位诱导InGaAsP/InGaAsP多量子阱混杂(QWI)行为。在多量子阱(MQW)外延片表面,采用等离子体增强的化学气相沉积(PECVD)不同厚度的SiO_2,然后溅射5 nm Cu,在不同温度下进行快速热退火(RTA)诱发量子阱混杂。通过光荧光(PL)谱表征样品在QWI前后的变化。实验结果表明,当RTA温度小于700℃时,PL谱峰值波长只有微移,且变化与其他参数关系不大;当RTA温度大于700℃时,PL谱峰值波长移动与介质层厚度和RTA时间都密切相关,当SiO_2厚度为200 nm,退火温度为750℃,时间为200 s时,可获得54.3 nm的最大波长蓝移。该种QWI方法能够诱导InGaAsP MQW带隙移动,QWI效果与InGaAsP MQW中原子互扩散激活能、互扩散原子密度以及在RTA过程中热应力有关。 相似文献
8.
单轴压应变量子阱红外探测器吸收波长的研究 总被引:1,自引:0,他引:1
研究了单轴压应力对GaAs/AlGaAs/GaAs量子阱红外探测器(QWIP)吸收波长的影响。以量子阱电子干涉方法以及单轴压应力作用下量子阱应变理论为基础,分析了GaAs/AlGaAs/GaAs量子阱导带中子能级与应变的关系。理论上计算了单轴应力下四个QWIP吸收波长与应变的关系。结果表明,E1与E<1>能级之间的吸收波长和E(1)与EF能级之间的吸收波长随应变的增大而减小的幅度比E1与EF能级之间的吸收波长和E(0)与E1能级之间吸收波长随应变的增大减小的幅度大。 相似文献
9.
提出P型张应变Si/SiGe量子阱红外探测器(QWIP)结构,应用k·P方法计算应变Si/SiGe量子阱价带能带结构和应变SiGe合金空穴有效质量.结果表明量子阱中引入张应变使轻重空穴反转,基态为有效质量较小的轻空穴态,因此P型张应变Si/SiGe QWIP与n型QWIP相比具有更低的暗电流;而与P型压应变或无应变QWIP相比光吸收和载流子输运特性具有较好改善.在此基础上讨论了束缚态到准束缚态子带跃迁型张应变p-Si/SiGe QWIP的优化设计. 相似文献
10.
量子阱红外探测器掺杂阱中能级的计算 总被引:1,自引:1,他引:0
量子阱中能级位置的确定是获得量子阱红外探测器其它设计参数的基础。为了提供足够的载流子跃迁,阱层一般为重掺杂层。重掺杂使半导体材料禁带宽度变窄,从而改变量子阱中能级的位置。通过对不同温度、量子阱区不同掺杂浓度条件下的量子阱材料PL 谱进行测量,得出PL 谱峰值波长对应的电子跃迁峰值能量,它与阱中基态能级的位置有关。分别计算了考虑和不考虑禁带变窄效应时的电子跃迁峰值能量,并与实验结果相比较,可以看出考虑禁带变窄效应时与实验结果相吻合,因此掺杂量子阱区能级的计算需要考虑禁带变窄效应,这样可以较为精确的得出阱中能级的位置。 相似文献
11.
提出P型张应变Si/SiGe量子阱红外探测器(QWIP)结构,应用k·P方法计算应变Si/SiGe量子阱价带能带结构和应变SiGe合金空穴有效质量.结果表明量子阱中引入张应变使轻重空穴反转,基态为有效质量较小的轻空穴态,因此P型张应变Si/SiGe QWIP与n型QWIP相比具有更低的暗电流;而与P型压应变或无应变QWIP相比光吸收和载流子输运特性具有较好改善.在此基础上讨论了束缚态到准束缚态子带跃迁型张应变p-Si/SiGe QWIP的优化设计. 相似文献
12.
D.K. Sengupta W Fang J.I. Malin A.P. Curtis T. Horton H.C. Kuo D. Turnbull C.H. Lin J. Li K.C. Hsieh S.L. Chuang I. Adesida M. Feng S.G Bishop G.E. Stillman J.M. Gibson H. Chen J. Mazumder H.C. Liu 《Journal of Electronic Materials》1997,26(1):43-51
The effect of rapid thermal annealing (RTA) on important detector characteristics such as dark current, absolute response,
noise, and detectivity is investigated for quantum-well infrared photodetectors (QWIP) operating in the 8–12 μm wavelength
regime. A comprehensive set of experiments is conducted on QWIPs fabricated from both as-grown and annealed multiple-quantum-well
structures. RTA is done at an anneal temperature of 850°C for 30 s using an SiO2 encapsulant. In general, a decrease in performance is observed for RTA QWIPs when compared to the as-grown detectors. The
peak absolute response of the annealed QWIPs is lower by almost a factor of four, which results in a factor of four decrease
in quantum efficiency. In addition, a degraded noise performance results in a detectivity which is five times lower than that
of QWIPs using asgrown structures. Theoretical calculations of the absorption coefficient spectrum are in excellent agreement
with the experimental data. 相似文献
13.
多量子阱红外探测器是一种新型的利用子带跃迁机制的探测器件,具有非常高的设计自由度。GaN/Al(Ga)N量子阱由于大的导带带阶,超快的电子驰豫时间,超宽的红外透明区域以及高的声子能量,使得其成为继GaAs量子阱红外探测器之后又一潜在的探测材料结构。文中详细综述了国内外关于GaN基量子阱红外子带吸收及其探测器件的研究进展。首先介绍了量子阱红外探测器的工作原理及其选择定则,接着从极性GaN基多量子阱、非极性或半极性GaN基多量子阱以及纳米线结构GaN基多量子阱三个方面回顾当前GaN基多量子阱红外吸收的一些重要研究进展,包括了从近红外到远红外甚至太赫兹波段范围的各种突破。最后回顾了GaN基多量子阱红外探测器件的研究进展,包括其光电响应特性和高频响应特性,并对其未来的发展进行总结和展望。 相似文献
14.
D. K. Sengupta M. B. Weisman M. Feng S. L. Chuang Y. C. Chang L. Cooper I. Adesida I. Bloom K. C. Hsieh W. Fang J. I. Malin A. P. Curtis T. Horton G. E. Stillman S. D. Gunapala S. V. Bandara F. Pool J. K. Liu M. McKelvey E. Luong W. Hong J. Mumolo H. C. Liu W. I. Wang 《Journal of Electronic Materials》1998,27(7):858-865
We present in this article device characteristics of molecular beam epitaxy grown GaAs/AlGaAs quantum well infrared photodetectors
(QWIP) on a semi-insulating GaAs substrate and on a GaAs-on-Si substrate grown by metalorganic chemical vapor deposition (MOCVD).
Important issues for QWIP application such as dark current, spectral response, and absolute responsivity were measured. We
find that the detector structure grown on a GaAs-on-Si substrate exhibits comparable dark current and absolute responsivity
and a small blue shift in the spectral response. This is the first demonstration of long wavelength GaAs/AlGaAs quantum well
infrared photodetector using MOCVD grown GaAs-on-Si substrate and the performance is comparable to a similar detector structure
grown on a GaAs substrate. 相似文献
15.
用固态分子束外延技术生长了高应变In0.45Ga0.55As/GaAs量子阱材料. 研究了快速热退火对高应变InGaAs/GaAs量子阱材料光学性质的影响. 本文采用假设InGaAs/GaAs量子阱中的In-Ga原子扩散为误差函数扩散并解任意形状量子阱的薛定谔方程的方法,对不同退火温度下InGaAs/GaAs量子阱室温光致发光峰值波长拟合,得到了In原子在高应变InGaAs/GaAs量子阱中的扩散系数以及扩散激活能(0.88eV) . 相似文献
16.
D.A. May-Arrioja N. Bickel M. Torres-Cisneros P. LiKamWa 《Microelectronics Journal》2009,40(3):574-1959
The intermixing characteristics of three widely used combinations of InP-based quantum wells (QW) are investigated using the impurity-free vacancy disordering (IFVD) technique. We demonstrate that the bandgap energy shift is highly dependent on the concentration gradient of the as-grown wells and barriers, as well as the thickness of the well, with thinner wells more susceptible to interdiffusion at the interface between the barrier and well. According to our results, the InGaAsP/InGaAsP and InGaAs/InP are well suited for applications requiring a wide range of bandgap values within the same wafer. In the case of the InGaAs/InGaAsP system, its use is limited due to the significant broadening of the photoluminescence spectrum that was observed. The effect of the top InGaAs layer over the InP cladding is also investigated, which leads to a simple way to obtain three different bandgaps in a single intermixing step. 相似文献
17.
QUANTUM MECHANICAL MODEL AND SIMULATION OF GaAs/AlGaAs QUANTUM WELL INFRARED PHOTODETECTOR—Ⅱ ELECTRICAL ASPECTS 总被引:3,自引:2,他引:1
IntroductdonInthefirstpart ,wehavediscussedtheopiticalaspectsaboutthequantumwellinfraredphotodetec tor .Herewecontinuediscussionsabouttheelectricalaspectesofthedevicemodelandsimulation .1 DarkCurrentandPhotocurrentDistributedeffectsofexternalbiasacrossth… 相似文献
18.
We studied p-type GaAs/AIGaAs multiple quantum well (MQW) materials as a possible alternative to the current n-type GaAs/AIGaAs
MQWs for infrared detection. The advantage of p-type MQWs is that absorption of infrared radiation at normal incidence is
not selection rule forbidden as it is for the n-type. We have verified that significant photoresponse occurs at normal incidence
in p-type MQWs. We studied changes in the photoresponse spectrum as a function of well width and temperature. The MQW heterostructures
were designed to use bound to continuum intersubband absorption in the GaAs valence band and to have a peak photoresponse
near 8 μm. The photoresponse spectrum was compared to the first theoretical model of the bound to continuum absorption in
p-type GaAs/ AlGaAs MQWs. The theoretical absorption curve was found to be in good qualitative agreement with the experimental
results. 相似文献
19.
采用MBE法制备了不同结构参数及不同阱中掺杂浓度的GaAs/AlxGa1-xAs量子阱红外探测器外延材料。通过对量子阱红外探测器材料特性和器件特性的实验测试及理论分析,研究了量子阱红外探测器的响应光谱特性,并通过薛定谔方程和泊松方程的求解,对掺杂对量子阱能级的影响做了研究。结果表明,由于应力导致的能带非抛物线性使得阱中能级发生了变化,从而引起吸收峰向高能方向发生了漂移,而阱中进行适度的掺杂没有对量子阱能级造成影响,光致发光谱实验结果与之吻合较好。在光电流谱的实验分析基础之上,分析了量子阱阱宽、Al组分与峰值探测波长λ的关系,为量子阱红外探测器的设计优化提供了参考。 相似文献
20.
C. A. Tran J. T. Graham J. L. Brebner R. A. Masut 《Journal of Electronic Materials》1994,23(12):1291-1296
We present results of the growth of InAsxP1−x/InP strained heterostructures by low pressure metalorganic vapor phase epitaxy. A large incorporation of arsenic into the
InAsP ternary was observed using tertiarylbutylarsine as precursor. High resolution x-ray diffraction, photoluminescence,
and optical absorption measurements for InAsP/InP strained multiple quantum wells reveal that the InAsP/InP interface is very
sensitive to growth interruption. A systematic study of a growth in terruption sequence designed to improve the InAs/InP interface
was carried out. For nonoptimal growth interruption procedures a large density of interface states is created, probably as
a consequence of compositional modifications within the interface region. We find that the absorption spectrum may reveal
a significant density of interface states. Thus, photoluminescence on its own is insufficient to characterize the interface
roughness even for structures showing narrow low-temperature photoluminescence peaks. We also observe an enhancement of the
As content for structures grown on InP (001) relative to those simultaneously grown on InP(001) two degrees off toward [100],
which suggests that the composition of As in the ternary is limited by its surface diffusion. 相似文献