生长温度对In0.53Ga0.47As/InP的LPMOCVD生长影响

利用LPMOCVD技术在InP衬底生长了InxGa1-xAs材料,获得表面平整．光亮的In0.53Ga0.47As外延层。研究了生长温度对InxGa1-xAs外延层组分、表面形貌、结晶质量、电学性质的影响。随着生长温度的升高,为了保证铟在固相中组分不变,必须增加三甲基铟在气相中的比例。在生长温度较高时,外延层表面粗糙。生长温度在630℃与650℃之间,X射线双晶衍射曲线半高宽最窄,高于或低于这个温度区间,半高宽变宽。迁移率随着生长温度的升高而增加,在630℃为最大值,然后随着生长湿度的升高反而降低。生长温度降低使载流子浓度增大,在生长温度大于630℃时载流子浓度变化较小。     

In0.53Ga0.47AS/In0.52Al0.48As量子阱中的正磁电阻效应

在低温强磁场条件下,对In0.53 Ga0.47 As/In0.52AI0.48As量子阱中的二维电子气进行了磁输运测试.在低磁场范围内观察到正磁电阻效应,在高磁场下这一正磁电阻趋于饱和,分析表明这一现象与二维电子气中的电子占据两个子带有关.在考虑了两个子带之间的散射效应后,通过分析低磁场下的正磁电阻,得到了每个子带电子的迁移率,结果表明第二子带电子的迁移率高于第一子带电子的迁移率.进一步分析表明,这主要是由两个子带之间的散射引起的.     

Ga0.47 In0.53 As—The material for high-speed devices

Electron transport properties of Ga_0.47In_0.53As are reviewed. The available physical constants of the material and results on electron mobility in bulk materials, 2deg systems and under hot-electron conditions are presented. Applications of the material in the construction offet’s and photo-conductive detectors are briefly discussed.     

基于silvaco-TCAD的In0.53Ga0.47As/InP红外探测器的仿真

采用silvaco-TCAD研究In0.53Ga0.47As/InP SAGCM-APD光电探测器,对探测器的结构参数对器件的电场分布、击穿电压和贯穿电压的影响进行仿真分析。研究表明电荷层对器件内部电场起到更好的调节作用,但过高的电荷层面密度会导致APD探测器的击穿电压与贯穿电压之差减小。倍增层厚度的增加使击穿电压先减小后增高,贯穿电压线性增加,同时耗尽层宽度变大,使器件电容减小。当倍增区厚度1 μm、偏压为-5 V时,器件电容密度达到了4.5×10-17 F/μm。反向偏置电压为30 V时,APD探测器在1.31 μm和1.55 μm波长下的响应度分别达到1 A/W和1.1 A/W     

Performance of In0.47Ga0.53As metal-semiconductor-metal hybrid receiver at 1.55 μm

We report on the performance at 1.55 m of a hybrid receiver combining an In_0.47Ga_0.53As metal-semiconductor-metal photodetector (with buried AllnAs buffer layer) with a GaAs MESFET preamplifier. A bit error rate of 10^-9 is measured at 1 Gbps with nonreturn to zero pseudorandom bit sequence (2¹⁵–1) at a received optical power of –19 dBm. Modification of the preamplifier design and a reduction of bond pad size could improve the sensitivity by 6–7 dB.     

InP/In0.53Ga0.47As/InP双异质结双极型晶体管的仿真与分析

运用Silvaco-TCAD软件构建了InP/In_(0.53)Ga_(0.47)As/InP双异质结双极型晶体管模型,研究了掺杂浓度、厚度以及温度对器件特性的影响.结果表明:双异质结双极型晶体管DHBT的开启电压能达到约0.4V,当浓度达到4×10^(19) cm^(-3)的时候,电流增益可以达到一个最佳状态,其峰值能达到约125左右,且浓度对截止频率以及最高振荡频率没有太大的影响;当增大基区厚度时,电流增益会减小,改变厚度能够使DHBT输出特性得以提升,并且提高基区电流的注入;双异质结双极型晶体管具有很好的温度稳定性.     

Gate-controlled electron–electron interactions in an In0.53Ga0.47As/InP quantum well structure

We study the parabolic negative magnetoresistivity in a gated In_0.53Ga_0.47As/InP quantum well structure where the scattering potential is predominantly long range. This magnetoresistivity is caused by the electron–electron interactions and is fitted to estimate the interaction corrections to the Drude conductivity. These corrections are smaller than the prediction of a recent theory [I.V. Gornyi, A.D. Mirlin, Phys. Rev. Lett. 90 (2003) 076801], and can be quantitatively described by Altshuler’s theory.     

两个子带占据的In0.53Ga0.47As/In0.52Al0.48As量子阱中填充因子的变化规律

研究了低温(1.5K)和强磁场(0-13T)条件下,InP基In0.53Ga0.47As/In0.52Al0.48As量子阱中电子占据两个子带时填充因子随磁场的变化规律.结果表明,在电子自旋分裂能远小于朗道能级展宽的情况下,如果两个子带分裂能是朗道分裂能的整数倍时,即⊿E21=κ*ωc(其中κ为整数),填充因子为偶数;当两个子带分裂能为朗道分裂能的半奇数倍时,即⊿E21=(2κ 1*ω/2,填充因子出现奇数.     

In0.53 Ga0.47As/In0.52Al0.48As量子阱中双子带占据的二维电子气的输运特性

研究了不同沟道厚度的In0.53 Ga0.47As/In0.52Al0.48As量子阱中双子带占据的二维电子气的输运特性.在考虑了两个子带电子之间的磁致子带间散射效应后,通过分析Shubnikov-de Haas振荡一阶微分的快速傅里叶变换结果,获得了每个子带电子的浓度、输运散射时间、量子散射时间以及子带之间的散射时间.结果表明,对于所研究的样品,第一子带电子受到的小角散射更强,这与第一子带电子受到了更强的电离杂质散射有关.     

Optical and structural properties of molecular-beam epitaxially grown Ga0.47In0.53As/Al0.48In0.52As superlattices,emitting at 1.55 μm at room temperature

We have combined photoluminescence and absorption measurements with double crystal x-ray diffraction in order to study the influence of growth conditions on optical and structural properties of Ga_0.47In_0.53As/Al_0.48In_0.52As superlattices of 10.5 nm well width grown by molecular beam epitaxy on InPSn substrates. Superlattices with excellent structural properties can be grown even at low substrate temperatures of 500 °C, as indicated by narrow linewidths of the satellite peaks of the x-ray diffraction pattern of 20 to 25 s of arc (FWHM). However, elevated substrate temperatures are required to increase the intensity of the intrinsic luminescent subband transition at 77 K, to reduce the luminescence linewidth to 12 meV (FWHM), and to sharpen the absorption spectra. In addition to the absorption due to the steplike variation of the two-dimensional density of states, we observe excitonic transitions to the excitonic continuum at the subband edges.