Tunneling conductance of short-period superlattices with THz cavities

I. V. Altukhov ¹, S. E. Dizhur ¹, M. S. Kagan ¹, N. A. Khvalkovskiy  ¹, S. K. Paprotskiy ¹, N. D. Il’inskaya ², A. A. Usikova ², Yu. M. Zadiranov ², A. D. Buravlev ², A. P. Vasil’iev ², V. M. Ustinov ², A. N. Baranov ³, R. Teissier ³

  ¹ Kotel’nikov Institute of Radio Engineering and Electronics, Russian Ac. Sci., Moscow, Russia
² Ioffe Physico-Technical Institute, Russian Ac. Sci., St. Petersburg, Russia
³ IES, Université Montpellier 2, CNRS, Montpellier, France

The paper is received on November 28, 2016

 

Abstract. The effect of THz optical cavity on the resonant and non-resonant tunneling in short-period superlattices (SLs) was observed. The MBE grown InAs/AlSb and GaAs/AlAs SLs consisted, respectively, of 60 and 100 periods sandwiched between heavily doped cap layer and the substrate. The metallic contacts to the structure had the form of a ring and formed a distributed cavity for a free-space wavelength of 110 to 160 μm. The measurements were performed mainly at room T. The periodic maxima observed in current-voltage characteristics of resonator SL structures at the non-resonant tunneling were explained by the Purcell effect – the enhancement of spontaneous emission rate for optical transitions between confined levels within QWs at resonant frequencies of the cavity. The effect of the optical cavity is observed also in the region of miniband transport at moving domain formation. A change of the cavity quality led to a change in the shape of I-V curve. The reason for this change can be the high enough alternating field generated in the cavity, which shifts the operating point due to the rectification of ac field because of strong nonlinearity of the SL. This result points at the excitation of THz cavity by the negative resistance of SL with electric domains.

Key words: THz generation, THz cavity, superlattices, Purcell effect.

References

1.      Andronov A.A. Hot electrons in semiconductors and submillimeter waves (review). Sov. Phys. Semicond., 1987, Vol. 21, p. 701.

2.      Köhler R., Tredicucci A., Beltram F., Beere H.E., Linfield E.H., Davies A.G., Ritchie D.A., Iotti R.C., Rossi F. Terahertz semiconductor-heterostructure laser. Nature, 2002, Vol. 417, p. 156. DOI: 10.1038/417156a

3.      Walther C., Fisher M., Scalari G., Terazzi R., Hoyler N. and Faist J. Quantum cascade lasers operating from 1.2 to 1.6 THz. Applied Physics Letters, 2007, Vol. 91, p. 131122. DOI: 10.1063/1.2793177

4.      Scalari G., Terazzi R., Giovannini M., Hoyler N. and Faist J. Population inversion by resonant tunneling in quantum wells. Applied Physics Letters, 2007, Vol. 91, p. 032103. DOI: 10.1063/1.2759271

5.      Kumar S., Hu Q., and Reno J.L. 186 K operation of terahertz quantum-cascade lasers based on a diagonal design. Applied Physics Letters, 2009, Vol. 94, p. 131105. DOI: 10.1063/1.3114418

6.      Pavlov S.G., Zhukavin R.Kh., Orlova E.E., Shastin V.N., Kirsanov A.V., Huebers H.-W., Auen K. and Riemann H. Emission from Donor Transitions in Silicon. Phys. Rev. Lett., 2000, Vol. 84, p. 5220. ISSN: 00319007

7.      Altukhov I.V., Kagan M.S., Korolev K.A., Sinis V.P., Chirkova E.G., Odnoblyudov M.A., Yassievich I.N. Resonant acceptor states and terahertz stimulated emission of uniaxially strained germanium. Journal of Experimental and Theoretical Physics, 1999, Vol. 88, Issue 1, pp. 51-57. ISSN: 10637761

8.      Kagan M. S., Altukhov I. V., Sinis V. P., Chirkova E. G., Yassievich I. N. and Kolodzey J. Terahertz Stimulated Emission from Strained p-Ge and SiGe/Si Structures. Journal of Communications Technology and Electronics, 2003, Vol. 48, Issue 9, pp. 1047-1054. ISSN: 10642269

9.      Kagan M.S., Altukhov I.V., Sinis V.P., Chirkova E.G., Paprotskiy S.K., Yassievich I.N., Odnoblyudov M.A., Prokofiev A.A., and Kolodzey J. Stimulated THz Emission of Strained p-Ge and SiGe/Si Quantum-Well Structures Doped with Shallow Acceptors. ECS Trans., 2006, Vol. 3, p. 745. DOI: 10.1149/1.2355869

10.    Feiginov M., Kanaya H., Suzuki S., and Asada M. Operation of resonant-tunneling diodes with strong back injection from the collector at frequencies up to 1.46 THz. Applied Physics Letters, 2014, Vol. 104, Issue 24, p. 243509. DOI: 10.1063/1.4884602

11.    Kanaya H., Sogabe R., Maekawa T., Suzuki S., Asada M. Fundamental oscillation up to 1.42 THz in resonant tunneling diodes by optimized collector spacer thickness. Journal of Infrared, Millimeter, and Terahertz Waves, 2014, Vol. 35, Issue 5, pp. 425-431. DOI: 10.1007/s10762-014-0058-z

12.    Klappenberger F., Alekseev K.N., Renk K.F., Scheuerer R., Schomburg E., Allen S.J., Ramian G.R., Scott J.S.S., Kovsh A., Ustinov V., Zhukov A. Ultrafast creation and annihilation of space-charge domains in a semiconductor superlattice observed by use of Terahertz fields. European Physical Journal B, 2004, Vol. 39, Issue 4, June 2004, Pages 483-489. DOI: 10.1140/epjb/e2004-00221-y

13.    Alekseev K.N., Gorkunov M.V., Demarina N.V., Hyart T., Alexeeva N.V., Shorokhov A.V. Suppressed absolute negative conductance and generation of high-frequency radiation in semiconductor superlattices. Europhysics Letters, 2006, Vol. 73, Issue 6, pp. 934-940. DOI: 10.1209/epl/i2005-10484-4

14.    Thim H.W. Linear microwave amplification with Gunn Oscillators. IEEE Trans. on Electron Devices, 1967, Vol. ED-14, pp. 517 — 522.

15.    Hakki B.W. Amplification in Two — Valley Semiconductors. J. Appl. Phys., 1967, Volume 38, ¹ 2, p. 808.

16.    Zhdanova N.G., Kagan M.S., Kalashnikov S.G. Impedance of a semiconductor with a static high-field domain. Sov. Phys. Semicond., 1974, Vol. 8, I - p. 1731, II - p. 1736.

17.    Kagan M.S., Landsberg E.G., Chernyshov I.V. Negative conductivity due to vibrations of the wall of a static domain. Sov. Phys. Semicond., 1984, Vol. 18, p. 615.

18.    Altukhov I.V., Vasil'ev N.A., Kagan M.S., Kalashnikov S.G., Kukushkin V.V., Lukash V.S. Two-frequency oscillation in Gunn diodes. Sov. Phys. Semicond., 1979, Vol. 13, pp. 1148-1154.

19.    Altukhov I.V., Kagan M.S., Kalashnikov S.G., Kukushkin, V.V., Solyakov, V.N. Microwave oscillation modes of Gunn diodes above transit frequency. Sov. Phys. Semicond., 1979, Vol. 13, Issue 12, pp. 1356-1360. ISSN: 00385700

20.    Altukhov I.V., Galchenkov L.A., Kagan M.S., Kukushkin V.V. Electromagnetic waves in ring semiconductor structures with a moving Gunn domain. Sov. Phys. Semicond., 1985, Vol. 19, p. 1286.

21.    Altukhov I.V., Kagan M.S., Kalashnikov S.G., Kukushkin V.V., Ovechkin S.M. Electromagnetic wave amplification by Gunn diodes with moving domains. Sov. Tech. Phys. Lett., 1980, Vol. 6, p. 237.

22.    Wacker A. Semiconductor superlattices: A model system for nonlinear transport. Physics Reports, 2002, Vol. 357, Issue 1, pp. 1-111. ISSN: 03701573

23.    Andronov A.A., Dodin E.P., Zinchenko D.I., Nozdrin Y.N. Transport in GaAs/Al x Ga1-x As superlattices with narrow forbidden minibands: Low-frequency negative differential conductivity and current oscillations. Semiconductors, 2009, Vol. 43, Issue 2, pp. 236-244. DOI: 10.1134/S1063782609020225

24.    Purcell E.M. Spontaneous emission probabilities at radio frequencies. Phys. Rev., 1946, Vol. 69, p. 681.

25.    Kippenberg T.J., Tchebotareva A.L., Kalkman J., Polman A., and Vahala K.J. Purcell-factor-enhanced scattering from Si nanocrystals in an optical microcavity. Phys. Rev. Lett., 2009, Vol. 103, p. 027406. DOI: 10.1103/PhysRevLett.103.027406

26.    Altukhov I.V., Kagan M.S., Kalashnikov S.G., Kukushkin V.V., Landsberg E.G. Electrical instability of a semicondutor with a negative differential conductivity due to simultaneous heating of electrons by static and alternating electric fields. Sov. Phys. Semicond., 1978, Vol. 12, pp. 172-179.