Terahertz electroluminescence under conditions of shallow acceptor breakdown in germanium

Terahertz photoluminescence from GaAs doped with shallow donors at interband excitation

“…This calculated spectrum was obtained using the model of radiative transitions of electrons from continuum to discrete states of a hydrogen atom, 11 modified taking into account the donor binding energy. In accordance with the model, the optical transitions to excited impurity states are less significant because of the transition probability is proportional to 4 , where is the energy of the transition. The intracenter optical transitions of the 2P → 1S type presumably contribute to the THz emission also but due to considerable inhomogeneous broadening they are not clearly resolved and can be seen only as a relatively weak low-energy shoulder of the main emission band ͑see Fig.…”

“…One of the schemes to generate THz radiation relies upon optical transitions between the energy levels of shallow impurities in semiconductors and has been demonstrated under the conditions of impact ionization of impurity centers [1][2][3][4][5][6] or impurity photoionization by optical pumping the transition "impurity ground state-conduction or valence band." 7 Here we introduce, different than cited above, mechanism of THz emission exploiting band-to-band excitation of GaAs doped with shallow donors.…”

Linear Polarized Terahertz Emission under Electrical Breakdown of a Shallow Acceptor in Uniaxially Deformed Germanium

“…from the 4Γ − 8 state) to the ground state. The emission at 13 meV is caused by the transitions of hot holes from the valence band to the impurity ground state (see [2] for more details). It is necessary to note that the transitions from the first excited state of the acceptor (1Γ [5].…”

“…The impurity THz emission from Ge is quite intense and can be observed at electric fields as low as several V/cm. Although THz radiation accompanied by the breakdown of shallow impurities in Ge has long been found (see, e.g., [1]), its spectrum was only recently analyzed near the threshold of the breakdown of a shallow acceptor [2]. In Ref.…”

Terahertz Luminescence and Absorption under Impurity Breakdown in Quantum Wells and Strained Semiconductor Layers

“…The integrated THz electroluminescence (EL) intensity was measured by Ge:Ga detector in the spectral range of 60-110 µm at 4.2 K. Spectra of luminescence were recorded with spectral resolution of 0.6 meV using pump-out Fourier spectrometer operating in step scan mode described elsewhere [1]. A liquid helium cooled silicon bolometer equipped with band pass optical filter to provide operation in the spectral range of 5-350 cm −1 served as the detector of THz radiation.…”