俄歇复合对同质结InGaAs探测器探测率的影响

通过对InGaAs材料的俄歇(Auger)复合机制的理论分析,给出了少子寿命与材料组分、温度和载流子浓度的关系,从而得到材料参数等对InGaAs探测器的探测率影响的结果,优化材料参数和器件结构可抑制Auger复合机制,提高InGaAs探测器的探测率.     

Cd_xHg_(1-x)Te晶体杂质导电区的载流子复合

研究了85K时,x=0.195～0.22,平衡载流子浓度n_0=3×10~(14)～6×10~(15)厘米~(-3)的n型Cd_xHg_(1-x)Te晶体中的带间俄歇复合。导出实现杂质导电区寿命最佳值的条件。计算了τ与组分和掺杂的关系。讨论了光灵敏度过低的样品中,体材料局部中心和微小不均匀度参加复合的可能性。     

InAsSb势垒阻挡型红外探测器暗电流特性研究

计算了不同温度下由辐射复合和俄歇复合决定的InAsSb材料的载流子寿命,结果表明,低温下n型InAsSb材料的载流子寿命受限于辐射复合过程,而高温下InAsSb材料的载流子寿命取决于Auger 1复合过程。讨论了势垒阻挡型器件的暗电流解析模型及暗电流抑制机理,通过在nBn吸收层的另一侧增加重掺杂的n型电极层形成nBnn⁺结构对吸收区内的载流子进行耗尽,吸收区少数载流子浓度降低约两个数量级,从而进一步降低器件暗电流。成功制备了InAsSb-基nBnn⁺器件,150 K下器件暗电流低至3×10^-6 A/cm²,采用势垒结构器件的暗电流解析模型对150 K下器件的暗电流进行拟合分析,结果表明由于势垒层为p型掺杂,在吸收层形成耗尽区,导致器件中的产生复合电流并没有完全被抑制,工作温度低于180 K,器件暗电流受限于产生复合电流,工作温度高于180 K,器件暗电流受限于扩散电流。     

观测InGaAsP激光器的俄歇复合及载流子泄漏

俄歇复合和载流子泄漏已作为InGaAsP激光器和LED_s的温度灵敏性高和内量子效率低的原因而被提出。本文发表了通过测量载流子寿命和自发辐射率而获得辐射和俄歇复合率以及泄漏电流。发现俄歇复合率和泄漏电流强烈地依赖于掺杂程度。使用的器件是1.3μm InGaAsP双异质结激光器,其氧化物隔离接触条100μm,有源     

0.1电子伏特碲镉汞光电探测器

根据俄歇限制的带—带过程确定n 型材料中的载流子寿命的假设,分析了0.1电子伏特碲镉汞光电探测器的最终D~*。光导器件和光电二极管在热限制下作的定量比较表明,在70°K 以上时,光导器件能提供较良好的最终性能。然而,在较低温度下,受少数载流子扫出限制了的光导器件的D~*的极限表明,较好的性能潜力由光电二极管来提供。与获得这些最终D~*值相联系的问题,在目前的探测器设计和制造工艺的基础上加以探讨。     

镓铟砷／铝铟砷 QWLD中俄歇复合及其对T0的影响

修正了现行俄歇复合率的公式，并用之分析了晶格匹配ＧａＩｎＡｓ／ＡｌＩｎＡｓ异质材料系统在有无量子尺寸效应情况下的俄歇复合随载流子浓度和温度变化的行为。发现其阈值电流密度随温度的变化行为可分为特征温度不同的相邻两个温区，在较高温区，量子尺寸效应作用不大，在较低温区，量子尺寸效应反而降低了Ｔ０，并对此意外的现象提出初步的解释。     

文献简介索引

一、红外器件2001 InSb CID探测器工艺现状Status of CID InSb detector technology,M.D.Gibbons,Proc.SPIE,Vol.443(1984),pp.151-166.本文全面地评述锑化铟电荷注入器件的工艺及其机理,介绍InSb线列的制备方法、读出机理和性能,其线列可达512元。[义]2002 InAs(1-x)Sb_x的带间复合Band-to-band recombination in InAs(1-x)Sb_x,A.Rogalski,Poland,Infrared Phys.,1985,Vol.25,No.3,pp.551-560.计算了温度范围为77～300K和组分范围为0≤x≤1的InAs(1-x)Sbx中的辐射和俄歇复合载流子寿命,研究了直接能隙半导体中的可能俄歇复合机理。计算了俄歇率,包括n型半导体的玻尔兹曼统计量和非抛     

黄绿光发光二极管光衰性能研究

AlGaInP是GaAs基LED有源区主要材料,广泛应用于黄绿光至红光波段的LED。但在短波段尤其是黄绿光波段(565～575 nm),因其材料组成较接近间接带隙,其发光效率和稳定性存在问题。目前黄绿光功率衰减以俄歇复合损耗、非复合辐射中心损耗、载流子损耗为主。所以研究相同生长温度不同阱垒厚度、量子阱相同厚度不同生长温度、P型掺杂层掺杂浓度对发光光衰的影响。发现较薄的MQW阱垒厚度、较高的MQW生长温度及P-space后端P型层前端插入一层20 nm厚度,1.7×10~(18) cm~(-3)浓度的高掺杂层三种方案可以改善黄绿光发光二极管光衰性能。     

Hg_(1-x)Cd_xTe非线性光电导

利用连续运行的可调谐CO_2激光器,我们进行实验观察100K时N型Hg_(0.3)Cd_(0.2)Te带间跃迁的非线性光电导,着重研究了吸收系数、光激发非平衡载流子电子的浓度和复合寿命与光强的关系,分析指出,非线性光电导的产生可归结于动态Burstein-Moss效应和俄歇复合两过程.     

资料简介索引

红外技术 1001 Pb_(1-x)Sn_xTe(0≤x≤0.25)光伏探测器的少数载流子寿命和电阻面积乘积 Photovoltaic detectors Pb_(1-x)Sn_xTe(0≤x≤0.25) minority carrier lifetimes resistance-area product, M. Grudzien, Infrared Phys., 1081, Vol. 21, No. 1, pp. 1-8. 计算了Pb_(1-x)Sn_xTe中辐射复合和俄歇复合时的少数载流子寿命。计算是在77、200和300K温度下进行的,组分范围为0≤x≤0.30。在附录中比较了在100K温度下的实验结果和理论计算。探讨了在77K时     

Recombination in cadmium mercury telluride photodetectors

Cadmium mercury telluride is of considerable importance as a material for the detection of IR radiation. Carrier lifetime has been studied intensively as it is the principal factor controlling detector performance. Bulk lifetime is dominated by Auger processes in the narrow bandgap material sensitive between 8 and 14 μm, while it is dominated by radiative recombination in the wider bandgap material sensitive below 5 μm. Auger processes have been studied by observing the photoconductive decay as a function of temperature. This has led to an experimental determination of the overlap integral as 0.3. A fresh calculation of radiative lifetime by the van Roosbroek-Shockley method has led to an analytic expression that agrees well with observed lifetime. Recombination at discontinuities (contacts, surfaces and flaws introduced in processing) are of importance in the photoconductive detectors. Surface recombination velocity can be reduced to low values (less than 200 cm s⁻¹) in n-type material by obtaining an accumulated surface. The rate limiting processes are then transitions between filled surface states and holes. No such accumulation appears to occur at the contacts or lines of damage introduced in processing. As a result there is considerable recombination at these features. When lifetime is controlled by transit time effects it is called sweepout. In sweepout the dependence of ambipolar mobility on majority carrier concentration leads to novel effects. Auger lifetime is reduced in low carrier concentration samples by optical injection of carriers by the background. This effect has often been ascribed to Shockley-Read recombination. These results are being used in modelling of detector performance that reproduces most of the features seen in practical detectors.     

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     

The minority carrier lifetime in doped and undoped p-type Hg0.78Cd0.22Te liquid phase epitaxy films

This paper will describe: (1) the first comparative study of recombination mechanisms between doped and undoped p-type Hg_1-xCd_xTe liquid phase epitaxy films with an x value of about 0.22, and (2) the first determination of τ_A7 ⁱ/τ_A1 ⁱ ratio by lifetime’s dependence on both carrier concentration and temperature. The doped films were either copper- or gold-doped with the carrier concentration ranging from 2 x 10¹⁵ to 1.5 x 10¹⁷ cm^-3, and the lifetime varied from 2 μs to 8 ns. The undoped (Hg-vacancy) films had a carrier concentration range between 3 x 10¹⁵ and 8 x 10¹⁶ cm^-3, and the lifetime changed from 150 to 3 ns. It was found that for the same carrier concentration, the doped films had lifetimes several times longer than those of the undoped films, limited mostly by Auger 7 and radiative recombination processes. The ineffectiveness of Shockley-Read-Hall (SRH) recombination process in the doped films was also demonstrated in lifetime vs temperature curves. The important ratio of intrinsic Auger 7 lifetime to intrinsic Auger 1 lifetime, τ_A7 ⁱ/τ_A1 ⁱ, was determined to be about 20 from fitting both concentration and temperature curves. The reduction of minority carrier lifetime in undoped films can be explained by an effective SRH recombination center associated with the Hg vacancy. Indeed, a donor-like SRH recombination center located at midgap (E_v+60 meV) with a capture cross section for minority carriers much larger than that for majority carriers was deduced from fitting lifetime vs temperature curves of undoped films.     

Influence of temperature on Auger recombination lifetime in In1?xGaxAs materials

The influence of temperature and Ga composition on Auger recombination lifetime in n-type and p-type In1-xGaxAs materials is investigated through the simulation, assuming the concentrations of electrons and holes are 1017 cm-3 and 1018 cm-3, respectively. The results show that the temperature has little influence on Auger recombination lifetime of In1-xGaxAs materials at x<0.3. However, it has a great impact when x>0.3 and the effect is more obvious at a lower temperature. Moreover, Auger ...     

Effect of carrier recombination mechanisms on the open circuit voltage of n^＋-p GaInAsSb thermophotovoltaic cells

By analyzing the main recombination mechanisms in GaInAsSb materials, the dependences of the dark current density and open circuit voltage in n+-p GaInAsSb thermophotovoltaic cells on the recombination parameters, carrier concentration and cell thickness are calculated. The results show that the dark current mainly comes from p-region, and it is related with the surface and Auger recombinations in low and high carrier concentration ranges, respectively. The surface and Auger recombinations can b...     

Measurement of Auger recombination in silicon by laser excitation

A new experimental arrangement for the study of Auger recombination in silicon is described and analyzed. A relatively weakly absorbed YAG:Nd laser beam was used for excitation. The decay of the carrier concentration after the injection pulse was studied by measuring the recombination radiation in a direction perpendicular to the laser beam. At some distance from the injection surface the influence of surface recombination and diffusion is then negligible. It has previously been shown that in this geometry the carrier concentration distribution after the laser excitation is accurately described by an analytical expression which accounts for attentuation of the laser beam by both interband and free carrier absorption. Thus the local carrier concentration in the sample can be computed to a high degree of accuracy, which is essential in the determination of the Auger recombination coefficient from decay measurements. Furthermore, this experimental geometry eliminates the problems with laser stray light. Assumptions regarding the influence of surface recombination and diffusion are not necessary in the interpretation of the experiments. The method is usable for silicon in the temperature interval 150–400 K. Preliminary measurements of the Auger coefficient at room temperature are reported.     

Minority carrier diffusion length in liquid epitaxial GaP

Using a Schottky diode photocurrent technique, investigations have been made of the room temperature value of minority carrier diffusion length in liquid epitaxial GaP grown on both (111) and (100) oriented pulled GaP substrates. Results are presented for undoped layers and layers doped separately with S, S and N, Te, Zn, and Zn and O, to cover a range of impurity concentration in the GaP. The measured values of minority carrier diffusion length are found to depend on the concentration of the dominant impurity and, for the undoped and Zn doped layers, also on the growth orientation of the substrate. From the dependence of the minority carrier diffusion length on majority carrier concentration we infer the dominant room temperature recombination process in the layers. In our undoped layers this process is believed to correspond to recombination via residual Si substituted on P sites. In Te, S, Zn, and Zn, O doped layers the dominant recombination mechanism can be attributed to a non-radiative band-band Auger process, although in the case of the Zn, O doped layers a competing recombination process is observed which is believed to correspond to recombination via centres formed by unpaired O and Zn defects. The lifetime for this competing process is predicted to be sensitive to annealing.     

Experimental comparison of localized and free carrier Auger recombination in silicon

The lifetimes of excitons bound to different shallow impurities in silicon have been measured. A comparison with a theoretical calculation shows that a 3-particle Auger process dominates the recombination. In the case of high carrier concentration the lifetime of free carriers is also governed by the Auger recombination. In contrast to the bound excitons this Auger process cannot be of first order but an additional excitation, probably a phonon, must be involved. It turns out, indeed, that the excitonic Auger recombination is more “effective” than the band-to-band transition, as expected for a lower order process. A comparison of the results for the highly doped material with those for highly excited pure samples (electron-hole drops, EHD) shows that also in this case the Auger recombination dominates.