中国激光, 2010, 37 (3): 658, 网络出版: 2010-03-11   

砷化镓内电子谷间散射引起的增益

Electrons Intervalley Transfer Gain in Bulk GaAs
作者单位
1 上海理工大学 光电信息与计算机工程学院,上海 200093
2 上海交通大学 微电子学院,上海 200240
摘要
运用时域太赫兹波谱法,低温(10 K)高电场下本征砷化镓中受飞秒激光脉冲激发的电子所辐射出的太赫兹波被准确地测量出来。从样品中辐射出的和电子加速度/减速度成正比的太赫兹电磁波,表现出双极特性。通过分析砷化镓中辐射出的太赫兹波的傅里叶变换谱,在实验上得到阶跃电场下的砷化镓内因电子谷间散射而引起的增益极限频率,可以达到约750 GHz(10 K)。同时通过测量极限频率和温度的关系,发现极限频率是电子经由纵光学声子从L谷到Γ谷的散射能量弛豫过程所需要的时间决定的。通过理论计算电子在Γ谷的弹道加速、电子谷间散射和电子经由纵光学声子连续散射在Γ谷的弛豫等过程的时间得出的增益极限频率与实验值吻合得较好。
Abstract
By using time-domain terahertz (THz) spectroscopy,the THz waveforms emitted from bulk GaAs photoexcited by femtosecond laser pulses under very high electric fields at 10 K have been recorded. It is clearly seen that the THz emission waveforms show a bipolar feature i.e.,an initial positive peak and a subsequent negative dip. Terahertz intervalley transfer gain under step-function-like input electric fields F has been obtained by calculating Fourier spectrum of the measured THz trace under various biased electric fields. We found it can reach 750 GHz for F> 50 kV/cm at 10 K. Furthermore,from the temperature dependence of the cutoff frequency for the gain,it is found that the cutoff frequency is governed by the energy relaxation process of electrons from L to Γ valley via successive longitudinal-optical phonon emission. The estimated cutoff frequencies,at 10 K by considering the time for electrons ballistic acceleration in Γ valley,intervalley transfer,relaxation in Γ valley via longitudinal-optical phonon scattering match the experimental results very well.
参考文献

[1] . K. Ridley,T. B. Watkins. The possibility of negative resistance effects in semiconductors[J]. Proc. Phys. Soc. Lon., 1961, 78(2): 293-304.

[2] . Hilsum. Transferred electron amplifiers and oscillators[J]. Proc. IRE, 1962, 50(2): 185-189.

[3] J. B. Gunn. Microwave oscillations of current in Ⅲ-V semiconductors[J]. Solid State Commun.,1993,88(11-12):883-886

[4] . Kroemer. Theory of Gunn effect[J]. Proc. IEEE, 1964, 52(12): 1736.

[5] . Reklaitis,L. Reggiani. Monte Carlo study of hot-carrier transport in bulk wurtzite GaN and modeling of a near-terahertz impact avalanche transit time diode[J]. J. Appl. Phys., 2004, 95(12): 7925-7935.

[6] . Gruzhinskis,E. Starikov,P. Shiktorov et al.. Hydrodynamic analysis of DC and AC hot-carrier transport in semiconductors[J]. Semicond. Sci. Technol., 1993, 8(7): 1283-1290.

[7] Y. K. Pozhela,L. Reggiani. Hot Electron Transport in Semiconductors[M]. Berlin:Springer-Verlag,1985

[8] 田震,王昌雷,栗岩锋 等. 基于光子晶体光纤飞秒激光器的紧凑型太赫兹时域光谱仪[J]. 中国激光,2008,35(3):477

    Tian Zhen,Wang Changlei,Li Yanfeng et al.. Compact THz time-domain spectroscopy based on photonic crystal fiber femtosecond laser[J]. Chinese J. Lasers,2008,35(3):477

[9] 郑芳华,刘欢,李喜福 等. 产生太赫兹辐射源的Nd∶YAG双波长准连续激光器[J]. 中国激光,2008,35(2):200-205

    Zheng Fanghua,Liu Huan,Li Xifu et al.. Simultaneous dual-wavelength quasi-continuous-wave laser-diode-end-pumped Nd∶YAG laser for terahertz wave sourse[J]. Chinese J. Lasers,2008,35(2):200-205

[10] 张兴宁,陈稷,周泽魁. 太赫兹时域光谱技术[J]. 激光与光电子学进展,2005,42(7):35-38

    Zhang Xingning,Chen Ji,Zhou Zekui. THz time-domain spectroscopy technology[J]. Laser & Optoelectronics Progress,2005,42(7):35-38

[11] 马成举,陈延伟,向军 等. 太赫兹辐射产生技术进展[J]. 激光与光电子学展,2007,44(4):56-61

    Ma Chengju,Chen Yanwei,Xiang Jun et al.. Progress in generation of terahertz radiation[J]. Laser & Optoelectronics Progress,2007,44(4):56-61

[12] 张影华,刘玉璞,陆培华 等. ps超高速电光采样[J]. 中国激光,1992,A19(3):176-179

    Zhang Yinghua,Liu Yupu,Lu Peihua et al.. Picosecond electro-optic sampling[J]. Chinese J. Lasers,1992,A19(3):176-179

[13] . Leitenstorfer,S. Hunsche,J. Shah et al.. Femtosecond charge transport in polar semiconductors[J]. Phys. Rev. Lett., 1999, 82(25): 5140-5143.

[14] . Leitenstorfer,S. Hunsche,J. Shah et al.. Femtosecond high-field transport in compound semiconductors[J]. Phys. Rev. B, 2000, 61(24): 16642-16652.

[15] . M. Zhu,T. Unuma,K. Shibata et al.. Femtosecond acceleration of electrons under high electric fieldsin bulk GaAs investigated by time-domain terahertz spectroscopy[J]. Appl. Phys. Lett., 2008, 93(4): 042116.

[16] 朱亦鸣,张大伟,何波涌 等. 利用时域太赫兹波谱法的超高电场下砷化镓内能带耦合现象研究[J]. 中国激光,2009,36(2):328-332

    Zhu Yiming,Zhang Dawei,He Boyong et al.. Strong band mixing in bulk GaAs under high electric field investigated by time-domain terahertz spectroscopy[J]. Chinese J. Lasers,2009,36(2):328-332

[17] . Shimada,K. Hirakawa,M. Odnoblioudov et al.. Terahertz conductivity and possible Bloch gain in semiconductor superlattices[J]. Phys. Rev. Lett., 2003, 90(4): 046806.

[18] . Sekine,K. Hirakawa. Dispersive terahertz gain of a nonclassical oscillator:Bloch oscillation in semiconductor superlattices[J]. Phys. Rev. Lett., 2005, 94(5): 057408.

[19] 朱亦鸣,贾晓轩,陈麟 等. 超低温高电场下GaAs的电子太赫兹功耗谱的研究[J]. 物理学报,2009,58(4):2692-2696

    Zhu Yiming,Jia Xiaoxuan,Chen Lin et al.. Terahertz power dissipation spectra of electrons in bulk GaAs under high electric fields at low temperature[J]. Acta Physica Sinica,2009,58(4):2692-2696

[20] . Das,R. Bharat. Hot electron relaxation times in two-valley semiconductors and their effect on bulk-microwave oscillators[J]. Appl. Phys. Lett., 1967, 11(12): 386-388.

[21] P. J. Bulman,G. S. Hobson,B. C. Taylor. Transferred Electron Devices[M]. London and New York:Academic Press,1972

倪争技, 陈麟, 王淑玲, 张大伟, 何波涌, 朱亦鸣. 砷化镓内电子谷间散射引起的增益[J]. 中国激光, 2010, 37(3): 658. Ni Zhengji, Chen Lin, Wang Shuling, Zhang Dawei, He Boyong, Zhu Yiming. Electrons Intervalley Transfer Gain in Bulk GaAs[J]. Chinese Journal of Lasers, 2010, 37(3): 658.

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