Probing States of a Double Acceptor in CdHgTe Heterostructures via Optical Gating

Nikolaev, I. D.; Svetikova, T. A. Uaman; Rumyantsev, V. V.; Жолудев, М. С.; Козлов, Д. В.; Morozov, S. V.; Dvoretsky, S. A.; Михайлов, Н. Н.; Гавриленко, В. И.; Иконников, А. В.

doi:10.1134/s0021364020100124

Cited by 5 publications

(2 citation statements)

References 29 publications

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“…Similar spectral features were also investigated in HgTe/CdHgTe QW structures using the 'optical gating'. This method allows driving the Fermi level across the bandgap by the illumination sample due to the effect of the persistent residual PC [25], and demonstrated that spectral features 1 and 2 are due to photoexcitation of the same center switching between two different charge states, rather than two singly charged acceptors with different binding energies. Note: * indicates that the structure was annealed in a helium atmosphere In the case of transitions to the band continuum, the shallow acceptor photoexcitation should result in a step-like feature followed by a wide band corresponding to the different high-energy states of the free holes in the valence band.…”

Section: Resultsmentioning

confidence: 99%

Photoconductivity spectroscopy of arsenic-related acceptors in HgCdTe

Ikonnikov,

Rumyantsev,

Sotnichuk

et al. 2023

Semicond. Sci. Technol.

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The arsenic impurity is widely considered to be the best choice for p-type doping of HgCdTe ternary alloys, which has been a formidable problem for decades. This work studies the terahertz photoconductivity (PC) of Hg1–xCdxTe with x ~ 0.22 doped with arsenic and subjected to the activation annealing to obtain p-type conductivity. In addition to the inevitable photoexcitation lines of mercury vacancies, which act as double acceptors, the spectra contain a distinctive line associated with the photoexcitation of the arsenic-related acceptor. In contrast to the predictions of the effective mass approximation, the binding energy of the acceptor is found to be about 25 meV. The possible reasons for this unexpectedly high chemical shift, which is not quite consistent with the data recently obtained by the photoluminescence and Hall effect measurements, are discussed.

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Section: Resultsmentioning

confidence: 99%

Photoconductivity spectroscopy of arsenic-related acceptors in HgCdTe

Ikonnikov,

Rumyantsev,

Sotnichuk

et al. 2023

Semicond. Sci. Technol.

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“…The acceptor states in MCT epitaxial layers and HgTe/CdHgTe heterostructures with p-type conductivity were also studied by photoconductivity (PC) measurements [14,15] in the THz domain. The PC spectra exhibited bands near 10 meV and 20 meV that were associated with the photoexcitation of neutral and singly ionized mercury vacancies, respectively.…”

Section: Introductionmentioning

confidence: 99%

Non-Radiative Transitions of Holes on Mercury Vacancies in Narrow-Gap HgCdTe

et al. 2022

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Mercury vacancies, acting as double acceptors, are the dominant point defects in ternary HgCdTe alloys. Though HgCdTe is one of the leading materials in infrared optoelectronics, the energy spectra of the vacancies are still a matter of some debate. This work investigated the rates at which holes are captured to a singly ionized mercury vacancy via acoustic phonon emission in narrow-gap Hg1−xСdxTe with technologically relevant x~0.22. Combined with the calculated rates of intracenter transitions, the data allow one to predict the most pronounced optical transitions in the emission spectrum of a double-charged acceptor. The results are sustained by the photoluminescence spectroscopy in the terahertz domain, allowing one to identify the emission band that is related to neutral vacancies.

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Bipolar persistent photoconductivity in HgTe/CdHgTe double quantum well heterostructures and its application for reversible change in the conductivity type

Nikolaev

Kazakov

Drozdov

et al. 2022

Journal of Applied Physics

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We report a detailed study of the bipolar persistent photoconductivity in an HgTe/CdHgTe double quantum well (DQW), which can be a perspective for studying topological states in these structures. Photoconductivity spectra measurements in the range of 1.1–3.1 eV as well as transport measurements under different illumination conditions were performed at T = 4.2 K. Based on the results, the processes occurring in the structure under illumination and leading to a change in the carrier concentration in the DQW have been established. They include interband generation in the CdTe cap layer and in the CdHgTe barrier layer and electron transitions from the spin-split band in the CdHgTe barrier layer to the conduction band in the CdTe cap layer. The presence of the CdTe cap layer and the appropriate cadmium fraction in the CdHgTe barrier layers have been shown to be the main factors determining the key features of the spectra. Finally, we suggest an effective method of controlling the conductivity type of HgTe/CdHgTe structures using light with different wavelengths.

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Probing States of a Double Acceptor in CdHgTe Heterostructures via Optical Gating

Cited by 5 publications

References 29 publications

Photoconductivity spectroscopy of arsenic-related acceptors in HgCdTe

Photoconductivity spectroscopy of arsenic-related acceptors in HgCdTe

Non-Radiative Transitions of Holes on Mercury Vacancies in Narrow-Gap HgCdTe

Bipolar persistent photoconductivity in HgTe/CdHgTe double quantum well heterostructures and its application for reversible change in the conductivity type

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