正照射与背照射InGaAs探测器的性能对比研究

首先介绍了InGaAs台面探测器的研究进展，然后为了验证利用台面结制作背照射器件的可行性，利用分子束外延（MBE）方法生长的掺杂InGaAs吸收层PIN InP／InGaAs／InP双异质结外延材料，通过台面制作、钝化、电极生长、背面抛光等工艺，制备了8元台面InGaAs探测器，并测试了正照射和背照射时，器件的Ⅰ-Ⅴ、信号和响应光谱。测试结果表明，正照射和背照射情况下，器件的响应信号差别不大，正照射下器件的平均峰值探测率为4．1×10^11cm·Hz^1/2·W^-1，背照射下器件的平均峰值探测率为4．0×10^11cm·Hz^1/2·W^-1，但背照射情况下器件的响应光谱在短波方向有更好的截止。     

正照射与背照射InGaAs探测器的性能对比研究

首先介绍了InGaAs台面探测器的研究进展，然后为了验证利用台面结制作背照射器件的可行性，利用分子束外延(MBE)方法生长的掺杂InGaAs吸收层PIN InP／InGaAs／InP双异质结外延材料，通过台面制作、钝化、电极生长、背面抛光等工艺，制备了8元台面InGaAs探测器，并测试了正照射和背照射时，器件的I-V、信号和响应光谱。测试结果表明，正照射和背照射情况下，器件的响应信号差别不大，正照射下器件的平均峰值探测率为4．1×1011cm·Hz1/2·W-1，背照射下器件的平均峰值探测率为4．0×1011cm·Hz1/2·W-1，但背照射情况下器件的响应光谱在短波方向有更好的截止。     

正、背照InGaAs探测器的性能对比研究

为了验证利用台面结制作背照射器件的可行性,利用分子束外延(MBE)方法生长的掺杂InGaAs吸收层PIN InP/InGaAs/InP双异质结外延材料,通过台面制作、钝化、电极生长、背面抛光等工艺,制备了8元台面InGaAs探测器,并测试了正照射和背照射时,器件的I-V、信号和响应光谱.测试结果表明,正照射和背照射情况下,器件的响应信号差别不大,正照射下器件的平均峰值探测率为4.13×1011cmHz1/2W-1,背照射下器件的平均峰值探测率为4×1011cmHz1/2W-1,但背照射情况下器件的响应光谱在短波方向有更好的截止.     

InGaAs纳米线雪崩焦平面探测器发展研究

基于InGaAs纳米线的光电探测器,由于其优异的性能而受到广泛的关注和研究。综述了InGaAs纳米线光电探测器的探测机理、材料结构、器件性能和当前的研究现状。讨论了InGaAs纳米线雪崩焦平面探测器结构设计、纳米线材料精密生长、纳米线材料的界面与缺陷控制、纳米线雪崩焦平面器件制备工艺等关键技术。对发展高光子探测效率、低噪声、高增益InGaAs纳米线雪崩焦平面探测器的前景进行了展望。     

InGaAs短波红外探测器研究进展

InxGa1-xAs材料属于Ⅲ-Ⅴ族化合物半导体合金材料,随In组分含量的不同,其光谱响应的截止波长可在0.87～3.5μm范围内变化,并具有高量子效率,加之成熟的MBE和MOVCD材料生长方式,很容易获得大面积高质量的外延材料,InGaAs材料因此成为一种重要的短波红外探测材料。InGaAs探测器可以在室温或近室温下工作,且具有较高的灵敏度和探测率,是小型化、低成本和高可靠性的短波红外探测系统的最佳选择,因此InGaAs短波红外探测器获得了飞速的发展和广泛的应用。同时对国内外InGaAs焦平面探测器发展状况和趋势进行了介绍。     

256元InGaAs线列红外焦平面及扫描成像

报道了用分子束外延(MBE)方法生长掺杂InGaAs的PIN InP/InGaAs/InP外延材料,通过台面制作、硫化处理、ZnS/聚酰亚胺双层钝化、电极生长等工艺,制备了256元正照射台面InGaAs线列探测器,278K时平均峰值探测率为1.33×1012 cmHz1/2W-1.测试了不同钝化方式探测器典型Ⅰ-Ⅴ曲线和探测率,硫化可以减小探测器暗电流,ZnS/聚酰亚胺双层钝化效果最好.并对ZnS/聚酰亚胺双层钝化InGaAs探测器进行了电子辐照研究.256元InGaAs探测器阵列与两个CTIA结构128读出电路互连并封装,在室温时,焦平面响应率不均匀性为19.3%.成功实现了室温扫描成像,图像比较清晰.     

短波红外InGaAs焦平面探测器研究进展

短波红外InGaAs焦平面探测器具有探测率高、均匀性好等优点,在航天遥感、微光夜视、医疗诊断等领域具有广泛应用。近十年来,中国科学院上海技术物理研究所围绕高灵敏度常规波长（0.9～1.7 μm） InGaAs焦平面、延伸波长（1.0～2.5 μm） InGaAs焦平面以及新型多功能InGaAs探测器取得了良好进展。在常规波长InGaAs焦平面方面,从256×1、512×1元等线列向320×256、640×512、4 000×128、1 280×1 024元等多种规格面阵方面发展,室温暗电流密度优于5 nA/cm2,室温峰值探测率优于5×1012 cm·Hz1/2/W。在延伸波长InGaAs探测器方面,发展了高光谱高帧频1 024×256、1 024×512元焦平面,暗电流密度优于10 nA/cm2和峰值探测率优于5×1011 cm·Hz1/2/W@200 K。在新型多功能InGaAs探测器方面,发展了一种可见近红外响应的InGaAs探测器,通过具有阻挡层结构的新型外延材料和片上集成微纳陷光结构,实现0.4～1.7 μm宽谱段响应,研制的320×256、640×512焦平面组件的量子效率达到40%@0.5 m、80%@0.8 m、90%@1.55 m;发展了片上集成亚波长金属光栅的InGaAs偏振探测器,其在0 °、45 °、90 °、135 °的消光比优于20:1。     

128×1线列InGaAs短波红外焦平面的研究

报道了用分子束外延(MBE)方法生长的掺杂InGaAs吸收层PIN InP/InGaAs/InP双异质结外延材料,通过干法刻蚀和湿法腐蚀相结合制作台面、硫化和聚酰亚胺钝化、电极生长等工艺,制备了128×1台面正照射InGaAs探测器阵列.测试了器件的变温I-V、响应光谱和探测率,在278K时平均峰值探测率为1.03×1012cmHz1/2W-1.实现了128元InGaAs探测器阵列与CTIA结构L128读出电路相互连,经封装后,在室温(291K)时成功测出128元响应信号.焦平面响应的不均匀性为18.3%,并对不均匀性产生的原因进行了分析.     

正照射与背照射InGaAs探测器的性能对比研究

首先介绍了InGaAs台面探测器的研究进展,然后为了验证利用台面结制作背照射器件的可行性,利用分子束外延(MBE)方法生长的掺杂InGaAs吸收层PIN InP/InGaAs/InP双异质结外延材料,通过台面制作、钝化、电极生长、背面抛光等工艺,制备了8元台面InGaAs探测器,并测试了正照射和背照射时,器件的Ⅰ-Ⅴ、信号和响应光谱.测试结果表明,正照射和背照射情况下,器件的响应信号差别不大,正照射下器件的平均峰值探测率为4.1×1011 cm·Hz1/2·W-1,背照射下器件的平均峰值探测率为4.0×1011 cm·Hz1/2·W-1,但背照射情况下器件的响应光谱在短波方向有更好的截止.     

宽带3—5μm量子阱红外探测器的研制

采用分子束外延方法在GaAs衬底上生长了n型掺杂的应变InGaAs/AlGaAs多量子阱结构,制作成 3—5μm波段的量子阱红外探测器 ,响应峰值波长 λp=4.2μm,响应带宽可达 Δλ/λ=50% ,500K黑体探测率 D*BB(500,1000,1 )达 1.7E10 cm.Hz1/2/W.     

Size effects in Auger recombination for InGaAs quantum-wirestructures

A theoretical investigation of Auger recombination in lattice-matched InGaAs/InGaAlAs quantum-wire structures is presented. The valence band structure is calculated by using a four-band Luttinger-Kohn Hamiltonian. CHCC, CHHH, CHHL and CHHS Auger processes are considered with the excited carrier being either in a confined (bound) state of the quantum wire, or an unconfined (unbound) state. The model uses Fermi statistics as well as a revaluation of the Coulomb interaction overlap integral for the calculation of the Auger recombination rate. Bound-unbound Auger processes are proven to be important nonradiative recombination mechanism in quantum-wire systems. It is also found that the Auger coefficient is much more sensitive to the well width in quantum-wire structures than in quantum-well structures     

The effect of temperature dependent processes on the performance of1.5-μm compressively strained InGaAs(P) MQW semiconductor diodelasers

We describe measurements of the threshold current I_th and spontaneous emission characteristics of InGaAs (P)-based 1.5-μm compressively strained multiple-quantum-well semiconductor lasers from 90 K to above room temperature. We show that below a break-point temperature, T_B≈130 K, I_th and its temperature dependence are governed by the radiative current. Above this temperature, a thermally activated Auger recombination process becomes the dominant recombination mechanism responsible for both I_th and its temperature sensitivity. At room temperature nonradiative Auger recombination is found to account for approximately 80% of the threshold current in these devices     

Performance limitation of short wavelength infrared InGaAs and HgCdTe photodiodes

The carrier lifetimes in In_xGa_1−xAs (InGaAs) and Hg_1−xCd_xTe (HgCdTe) ternary alloys for radiative and Auger recombination are calculated for temperature 300K in the short wavelength range 1.5<λ<3.7 μm. Due to photon recycling, an order of magnitude enhancements in the radiative lifetimes over those obtained from the standard van Roosbroeck and Shockley expression, has been assumed. The possible Auger recombination mechanisms (CHCC, CHLH, and CHSH processes) in direct-gap semiconductors are investigated. In both n-type ternary alloys, the carrier lifetimes are similar, and competition between radiative and CHCC processes take place. In p-type materials, the carrier lifetimes are also comparable, however the most effective channels of Auger mechanism are: CHSH process in InGaAs, and CHLH process in HgCdTe. Next, the performance of heterostructure p-on-n photovoltaic devices are considered. Theoretically predicted R_oA values are compared with experimental data reported by other authors. In_0.53Ga_0.47As photodiodes have shown the device performance within a factor often of theoretical limit. However, the performance of InGaAs photodiodes decreases rapidly at intermediate wavelengths due to mismatch-induced defects. HgCdTe photodiodes maintain high performance close to the ultimate limit over a wider range of wavelengths. In this context technology of HgCdTe is considerably advanced since the same lattice parameter of this alloy is the same over wide composition range.     

The effect of Auger mechanism on n+-p GaInAsSb infraredphotovoltaic detectors

In this paper, the theoretical analysis of the Auger mechanism in n⁺-p GaInAsSb infrared photovoltaic detectors is reported. The lifetime caused by the Auger mechanism is calculated depending on the compositions, temperature, and carrier concentration. We also analyze the effect of material parameters on the detectivity of the n ⁺-p GaInAsSb detectors. The calculated results show that the Auger mechanism could be suppressed by optimizing the material parameters, so that the performance of GaInAsSb infrared photovoltaic detectors is improved     

Auger recombination in long-wavelength strained-layer quantum-wellstructures

A model calculation of Auger recombination in strained-layer InGaAs-InGaAlAs and InGaAs-InGaAsP quantum-well structures is presented as an extension of an empirical Auger theory based on the effective mass approximation. The valence band effective masses around k_∥=0 are calculated by using a six-band Luttinger-Kohn Hamiltonian and the quasi-Fermi levels are determined with a self-consistent Poisson-Schrodinger solver under the effective mass approximation. Three basic Auger processes are considered with the excited carrier being in a bound state of the quantum well, as well as an unbound state. The empirical model includes Fermi statistics as well as a revaluation of the Coulomb interaction overlap integral in the Auger recombination rate. Bound-unbound Auger transitions are proved to be an important nonradiative recombination mechanism in strained-layer quantum-well systems. Our calculations of Auger coefficient are in reasonable agreement with the experimental data     

Contribution of Auger recombination to saturation of the light-current characteristics in high-power laser diodes (λ = 1.0–1.9 m m)

Spectral and light-current characteristics of lasers based on the asymmetric separate-confinement heterostructures InGaAs/InGaAsAl/InP and InGaAs/GaAs/AlGaAs/GaAs were studied in the pulsed mode of lasing. It is shown that, at high levels of current pumping, the charge-carrier concentration in the active region of semiconductor lasers for the near-infrared optical region increases beyond the oscillation threshold; drastic saturation of the light-current characteristics is observed. Processes occurring in lasers as the charge-carrier concentration increases beyond the lasing threshold are studied theoretically. It is established that, at high pump levels, the rate of stimulated recombination decreases, the lifetime of charge carriers increases, and both the concentration of emitted photons and the quantum yield of stimulated radiation decrease. It is shown that variations in stimulated recombination, the decrease in the quantum efficiency, and saturation of the light-current characteristic in semiconductor lasers at high levels of current pumping are caused by the contribution of the nonradiative Auger recombination.     

Radiative and nonradiative lifetimes in n-type and p-type 1.6 ?m InGaAs

Radiative and nonradiative lifetimes were deduced from measurements of lifetime and efficiency in 1.6 ?m InGaAs double-heterostructure active layers. The nonradiative rate is interpreted as due to the Auger effect. We find that the dominant Auger rate involves holes. This Auger rate increases with wavelength, accounting for the decrease in the temperature coefficient T0 with wavelength in InGaAsP material.     

Localized Auger Recombination in Quantum-Dot Lasers

We have calculated radiative and Auger recombination rates due to localized recombination in individual dots, for an ensemble of 10⁶ dots with carriers occupying the inhomogeneous distribution of energy states according to global Fermi-Dirac statistics. The recombination rates cannot be represented by simple power laws, though the Auger rate has a stronger dependence on the ensemble electron population than radiative recombination. Using single-dot recombination probabilities which are independent of temperature, the ensemble recombination rates and modal gain decrease with increasing temperature at fixed population. The net effect is that the threshold current density increases with increasing temperature due to the increase in threshold carrier density. The most significant consequence of these effects is that the temperature dependence of the Auger recombination rate at threshold is much weaker than in quantum wells, being characterized by a T₀ value of about 325 K. Observations of a strong temperature dependence of threshold in quantum dot lasers may have explanations other than Auger recombination, such as recombination from higher lying states, or carrier leakage.     

Radiative recombination of hot carriers in narrow-gap semiconductors

The mechanism of the radiative recombination of hot carriers in narrow-gap semiconductors is analyzed using the example of indium antimonide. It is shown that the CHCC Auger recombination process may lead to pronounced carrier heating at high excitation levels. The distribution functions and concentrations of hot carriers are determined. The radiative recombination rate of hot carriers and the radiation gain coefficient are calculated in terms of the Kane model. It is demonstrated that the radiative recombination of hot carriers will make a substantial contribution to the total radiative recombination rate at high carrier concentrations.     

A numerical calculation of auger recombination coefficients for InGaAsP/InP quantum well heterostructures

Auger recombination coefficients are calculated numerically for InGaAsP/InP quantum well heterostructures. In narrow quantum wells, the quasi-threshold and thresholdless mechanisms mainly contribute to the Auger recombination coefficient. For the processes involving two electrons and a heavy hole (CHCC) or an electron and two heavy holes with a transition of one of the holes to the spin-orbit split-off band (CHHS), the Auger recombination coefficients depend on temperature only slightly in a wide temperature range. The dependence of the Auger coefficient on the quantum well width is analyzed and found to be nonmonotonic.