Abstract-Suppressed Auger scattering and tunable light emission of Landau-quantized massless Kane electrons

D. B. But, M. Mittendorff, C. Consejo, F. Teppe, N. N. Mikhailov, S. A. Dvoretskii, C. Faugeras, S. Winnerl, M. Helm, W. Knap, M. Potemski & M. Orlita

https://www.nature.com/articles/s41566-019-0496-1

The Landau level laser was proposed long ago as a unique source of monochromatic radiation that would be widely tunable in the THz and infrared spectral ranges using a magnetic field. However, despite many efforts, this appealing concept never progressed to the design of a reliable device. This is because of the efficient Auger scattering of Landau-quantized electrons, an intrinsic non-radiative recombination channel that eventually gains over cyclotron emission in all materials studied so far (conventional semiconductors with parabolic bands, but also in graphene with massless electrons). Auger processes are favoured in these systems because the Landau levels (or their subsets) are equally spaced in energy. Here, we show that this scheme does not apply to massless Kane electrons in gapless HgCdTe, where undesirable Auger scattering is strongly suppressed and sizeable cyclotron emission is observed. The gapless HgCdTe thus appears as a material of choice for future Landau level lasers.

Abstract-Features of Photoluminescence of Double Acceptors in HgTe/CdHgTe Heterostructures with Quantum Wells in a Terahertz Range

D. V. Kozlov, V. V. Rumyantsev, A. M. Kadykov, M. A. Fadeev, N. S. Kulikov, V. V. Utochkin, N. N. Mikhailov, S. A. Dvoretskii, V. I. Gavrilenko, H.-W. Hubers, F. Teppe, S. V. Morozov,

https://link.springer.com/article/10.1134%2FS0021364019100114

The terahertz photoluminescence spectra of HgTe/CdHgTe heterostructure with quantum wells under interband optical excitation with a power of 3 to 300 mW have been studied in the temperature range of 30–100 K. The photoluminescence spectrum includes a band corresponding to quantum energies below the width of the band gap. The position of this band does not change with increasing temperature. This property allows attributing it to the capture of holes by acceptor centers. It has been shown that these acceptor centers are singly ionized mercury vacancies, which are double acceptors. A nonmonotonic dependence of the intensity of a signal of a long-wavelength photoluminescence band on the power of an exciting source has been revealed. A short-wavelength photoluminescence band corresponding to interband transitions appears with an increase in the exciting power. It has been shown that this effect is caused by the saturation of the number of partially ionized mercury vacancies with increasing pump intensity.

Abstract-Terahertz Spectroscopy of Two-Dimensional Semimetal in Three-Layer InAs/GaSb/InAs Quantum Well

S. S. Krishtopenko, S. Ruffenach, F. Gonzalez-Posada, C. Consejo, W. Desrat, B. Jouault, W. Knap, M. A. Fadeev, A. M. Kadykov, V. V. Rumyantsev, S. V. Morozov, G. Boissier, E. Tournié, V. I. Gavrilenko, F. Teppe

https://link.springer.com/article/10.1134%2FS0021364019020085

The features of terahertz photoluminescence and magnetoabsorption in magnetic fields up to 16 T in threelayer InAs/GaSb/InAs quantum wells with a band structure corresponding to a “two-dimensional semimetal” are studied. The comparison of the positions and amplitudes of the photoluminescence lines with the theoretical calculations of oscillator strengths for interband and intraband transitions performed using the eight-band Kane Hamiltonian indicates the existence of a nonradiative recombination channel associated with the overlap of the conduction and valence bands. The energies of interband and intraband Landau level transitions observed in the magnetoabsorption spectra are in good agreement with theoretical calculations, which confirms the predicted band structure.

Abstract-Reducing noise equivalent power in InP DHBT terahertz detector by biasing the collector

 N. Dyakonova,  D. Coquillat,   D. But,  C. Consejo, F. Teppe, W. Knap,  L. Varani,  S. Blin,  V. Nodjiadjim,   A. Konczy,

http://ieeexplore.ieee.org/document/7986010/


We present the low frequency noise and the photoresponse in InP double heterojunction bipolar transistor (DHBT) THz detectors. A current responsivity of 0.23 A/W and a noise equivalent power of 4·10−10 W/Hz1/2 have been measured at 1 kHz modulation frequency. The collector bias can substantially reduce the noise equivalent power.