Abstract-Terahertz luminescence and photoconductivity associated with the impurity electron transitions in GaAs/AlGaAs quantum wells

A D Kurnosova, I S Makhov,  D A Firsov, 

https://iopscience.iop.org/article/10.1088/1742-6596/1482/1/012019

The photoconductivity and photoluminescence spectra of GaAs/AlGaAs quantum wells doped with shallow donors are studied at low lattice temperatures. The optical electron transitions between the first electron subband and donor ground states, as well as between the excited and ground donor states, are revealed in the terahertz photoluminescence and photoconductivity spectra. The temperature evolution of the impurity-related photocurrent in the terahertz spectral range is also studied.

Abstract-Impurity-assisted terahertz photoluminescence in quantum wells under conditions of interband stimulated emission

I S Makhov, V Yu Panevin, D A Firsov, L E Vorobjev, A N Sofronov, M Ya Vinnichenko, N A Maleev, A P Vasil'ev,

http://iopscience.iop.org/article/10.1088/1742-6596/993/1/012017/meta

Terahertz and near-infrared photoluminescence under conditions of interband stimulated emission are studied in n-GaAs/AlGaAs quantum well laser structure. The observed terahertz emission is related to the optical transitions of nonequilibrium electrons from the first electron subband and excited donor states to donor ground states in quantum wells. The opportunity to increase the intensity of impurity-assisted terahertz emission due to interband stimulated emission with the participation of impurity centres is demonstrated.

Abstract-Terahertz absorption in GaN epitaxial layers under lateral electric field

R M Balagula1, M Ya Vinnichenko1, G A Melentev1, M D Moldavskaya1, V A Shalygin1, L E Vorobjev1,D A Firsov1, S N Danilov2 and S Suihkonen3


http://iopscience.iop.org/article/10.1088/1742-6596/741/1/012147
Variation of absorption of terahertz radiation in lateral electric field was investigated in GaN epitaxial layers. Different behaviour of the absorption modulation in electric field was observed for radiation polarized along electric field and perpendicular to it. Joint analysis of optical and transport measurements let us obtain field dependencies of mobility, electron concentration and absorption cross-section. For terahertz radiation polarized perpendicular to the electric field, results are in accordance with Drude model of free electron absorption. Another polarization demonstrates significant deviation that is yet to be studied more thoroughly.

Abstract-Terahertz reflection and emission associated with nonequilibrium surface plasmon polaritons in n-GaN

G A Melentyev1, V A Shalygin1, M D Moldavskaya1, V Yu Panevin1, L E Vorobjev1, D A Firsov1, H Nykänen2, L Riuttanen2, O Svensk2 and S Suihkonen2

http://iopscience.iop.org/1742-6596/586/1/01200

gamelen@spbstu.ru

1 Department of Physics of Semiconductors & Nanoelectronics, St. Petersburg Polytechnic University, Polytechnicheskaya 29, St. Petersburg 195251, Russia
2 School of Electrical Engineering, Aalto University, Otakaari 1, Espoo 02150, Finland 

Tag this article PDF (945 KB)

Surface plasmon polaritons are investigated in heavily doped n-GaN epitaxial layers. The grating etched on the surface of the epitaxial layer is used to convert photons into the surface plasmon polaritons and vice versa. The spectral study of reflection demonstrates the possibility of nonequilibrium surface plasmon polaritons excitation due to terahertz radiation scattering on the grating. Terahertz electroluminescence is investigated under lateral electric field. The luminescence spectrum demonstrates a significant contribution of nonequilibrium surface plasmon polariton scattering to terahertz radiation emission.