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利用Se电化学喷射炉产生的Se分子束,对分子束外延(MBE)GaAs掺杂,获得了载流子浓度为 10~(15)-10~(15)cm~(-3)的N型 GaAs. 载流子浓度 8.0 ×10~(15)-5.76 × 10~(15)cm~(-3)范围相应的室温迁移率为6350-5200cm~2/V·s.还研究了各种生长参数对载流子浓度的影响.对实验结果给予了定性的解释. 相似文献
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文报道了用红外透射光谱测量重掺杂化合物半导体n-GaAs和n-InP 载流子浓度的研究结果.给出了载流于浓度N和透射光谱截止波长λ_c的关系曲线,对应的经验公式为:对于 n-GaAs,N=1.09 × 10~(21)λ_c~(3.0623);n-InP,N=3.58 × 10~(20)λ_c~(-2.6689).本方法载流子浓度测量范围为 1.0×10~(17)≤N≤2.0 ×10~(19)cm~(-3),测量误差 ±10~15%.文中对测量条件进行了讨论,并给出了GaAs:Si样品载流子浓度径向分布的测量结果. 相似文献
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非抛物型能带半导体Hg_(1-x)Cd_xTe的本征载流子浓度 总被引:1,自引:1,他引:0
本文利用Kane的非抛物型能带模型及费密-狄拉克统计推得Hg_(1-x)Cd_xTe的本征载流子浓度公式为n_i=(1 3.25KT/Eg)9.56(10~(14))E_g~(3/2)T~(3/2) [1 1.9E_g~(3/4)exp(Eg/2kT)]~(-1), 该式适用于x=0.17~0.37,T≤300K范围,式中Eg(eV)=-0.295 1.87x-0.28x~2 (6-14x 3x~2)(10~(-4))T 0.35x~4。本文还测量了不同组份Hg_(1-x)CdxTe样品(x=0.19~0.251)在77K~300K温度范围的本征载流子浓度。将上述公式的计算结果与本文实验结果及其他作者实验结果相比较表明,该式在x=0.19~0.29,T=77~300K范围与实验符合很好。 相似文献
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MCT液相外延薄膜的生长和特性 总被引:1,自引:1,他引:0
用开管水平液相外延系统从富Te溶剂中生长了不同x值的MCT薄膜。经X射线衍射、Hall电学参数、红外光谱、扫描电镜、X射线能谱仪和电子通道花样分析测试,结果表明:外延薄膜表面平整,光学参数较好,纵向、横向组份均匀,晶体结构完整,电学参数较好,外延膜质量优良。短波材料(n型):载流子浓度3.54×10~(14)cm~(-3),迁移率1.63×10~4cm~2V~(-1)s~(-1);中波材料(n型):载流子浓度9.95×10~(14)cm~(-3),迁移率为1.76×10~4cm~2V~(-1)s~(-1);原生长波材料(n型):载流子浓度为2.15×10~(15)cm~(-3),迁移率2.00×10~4cm~2V~(-1)s~(-1)。 相似文献
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研究了基体偏压对 ITO 膜载流子浓度和迁移率影响的机理,并就载流子浓度和迁移率随偏压变化的实验结果与理论结果作了比较,两者基本吻合。获得了n_e=3.2×10~(20)cm~(-3),U_H=50cm~2V~(-1)s~(-1)的 ITO 膜。 相似文献
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本文用精确的双极晶体管一维模型叙述了禁带变窄、SRH(肖克莱-里德-霍尔)复合、俄歇复合、载流子-载流子散射和载流子-晶格散射等机构。利用这种晶体管作为一种工具,来研究决定发射极结深为1~8微米的器件的发射极效率的上述这些现象中的每一个现象的相对重要性。结果表明,禁带变窄对2微米或更浅的浅发射极器件是主要的影响因素,SRH 复合对发射极结深大于4微米的器件是主要的影响因素。所给出的计算也表明,对具有1~8微米发射极结深的器件来说,发射极表面浓度和高注入对电流增益有影响。结果表明,对1微米的发射极结深的器件,最佳表面浓度为5×10~(19)厘米~(-3),而对发射极结深大于4微米的器件,直到10~(21)厘米~(-3)还没有达到最佳值。 相似文献
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利用能带结构的Kane非抛物线近似值以及最近测得的重空穴质m_k和能带宽度E_g,计算了作为温度和组份函数的Hg_(1-x)Cd_xTe的本征载流子浓度。适于该计算的关系式为: n_i=[5.585-3.820x+1.753(10~(-3))T-1.364(10~(-3))xT]×(10~(14))E_0~(3/4)T~(3/2)exp(-E_g/2k_bT),在50<0,50相似文献
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硅中金受主能级特性的低温动态光伏研究 总被引:1,自引:0,他引:1
本文采用统计方法,对40K下金过补偿的P型硅单晶的动态光伏问题进行处理.计算结果与实验符合很好,从而探讨了硅中金受主能级在光离化、载流子复合过程中的行为,进而估算了金受主能级在hv=0.63eV光照下的光离化截面σ_i=6×10~(18)cm~2,及其对自由空穴的俘获截面σ_p=4×10~(15)cm~2. 相似文献
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BPSK (binary phase-shift keying) modulation with heterodyne demodulation is used in conjunction with convolutional codes to illustrate the feasibility of using coding to relax the laser linewidth requirements and improve the receiver sensitivity. The Viterbi algorithm is used, and the performance of the phase-locked loop in the carrier recovery circuit is studied. The results show that the relaxing factor of the laser linewidth can be larger than 12 at 10-9 bit error rate when a (2, 1) convolutional code with constraint length 11 is used. When the linewidth is fixed, this code can improve the receiver sensitivity by more than 9 dB 相似文献
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《Circuits and Systems II: Express Briefs, IEEE Transactions on》2009,56(1):11-15
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Chin-Yi Tsai Fang-Ping Shih Tien-Li Sung Tsu-Yin Wu Chih-Hsiung Chen Chin-Yao Tsai 《Quantum Electronics, IEEE Journal of》1997,33(11):2084-2096
We present a small-signal analysis of the modulation response by simultaneously considering the effects of spectral hole burning, carrier heating, and carrier diffusion capture-escape. An explicit form of the small-signal modulation response is obtained and the nonlinear gain coefficients associated with each physical process are defined. Further simplifications in our results will give analytical forms for calculating the resonant frequency and damping rate of the modulation response. One of the simplified versions of our results is shown to agree with previous investigations. The effects of the carrier dephasing time, energy relaxation time, and diffusion-capture-escape times on the high-speed performance of QW lasers are theoretically investigated 相似文献
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为解决高速QPSK信号全数字解调的技术瓶颈问题,采用模拟方案,研制了一种四次方环载波恢复电路,重点介绍了应用混频器上变频特性的宽带平方电路以及锁相环(PLL)载波提取电路的设计过程.测试结果表明,该载波恢复电路可以完成载频为720 MHz、码速率100 Mbit/s~1 Gbit/s范围的QPSK信号同步载波恢复,解决了高速信号相干解调中载波同步的关键技术问题. 相似文献
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Romero B. Esquivias I. Weisser S. Larkins E.C. Rosenzweig J. 《Photonics Technology Letters, IEEE》1999,11(7):779-781
We have extracted the ratio between the carrier capture and escape times, η, for In0.25Ga0.75As-GaAs lasers containing one, two, or three quantum wells, from high-frequency subthreshold impedance measurements at different temperatures. Our results show that the carrier capture process dominates over the diffusion along the confinement region in the overall transport/capture process. The obtained value for η is comparable to unity, and this fact has to be taken into account to obtain real material parameters, such as the carrier lifetime and the radiative recombination coefficient 相似文献
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By utilizing a two-step process to express the charge generation and separation mechanism of the transition metal oxides (TMOs) interconnector layer, a numerical model was proposed for tandem organic light emitting diodes (OLEDs) with a TMOs thin film as the interconnector layer. This model is valid not only for an n-type TMOs interconnector layer, but also for a p-type TMOs interconnector layer. Based on this model, the influences of different carrier injection barriers at the interface of the electrode/organic layer on the charge generation ability of interconnector layers were studied. In addition, the distribution characteristics of carrier concentration, electric field intensity and potential in the device under different carrier injection barriers were studied. The results show that when keeping one carrier injection barrier as a constant while increasing another carrier injection barrier, carri- ers injected into the device were gradually decreased, the carrier generation ability of the interconnector layer was gradually reduced, the electric field intensity at the interface of the organic/electrode was gradually enhanced, and the electric field distribution became nearly linear: the voltage drops in two light units gradually became the same. Meanwhile, the carrier injection ability decreased as another carrier injection barrier increased. The simulation re- sults agree with the experimental data. The obtained results can provide us with a deep understanding of the work mechanism of TMOs-based tandem OLEDs. 相似文献
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一种全数字高速率MPSK调制信号的载波频率估计方法 总被引:1,自引:0,他引:1
在高速数据传输系统中,载波恢复单元性能的好坏,直接影响着解调器的性能。为了解决高速率多相移键控(MPSK)调制信号在载波恢复过程中存在较大相位抖动的关键问题,给出了一种适用于一定多普勒变化范围的MP-SK信号的开环频率估计算法。与此同时,给出了相应的载波恢复单元的实现方法。在文章的最后,给出了该算法的仿真结果。此种算法不但可以应用于全数字载波恢复系统,也可以结合传统的锁相环应用。 相似文献