Deep-level optical spectroscopy of ZnTe

Kvit, A.; Medvedev, S. A.; Klevkov, Yu. V.; Зайцев, В. В.; Onishchenko, E. E.; Klokov, Andrey; Багаев, В. С.; Tsikunov, A. V.; Perestoronin, A. V.; Yakimov, M. V.

doi:10.1134/1.1130449

Cited by 9 publications

(4 citation statements)

References 8 publications

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“…Compared with the emission of sample A with 1.15% In, this PL shows infrared emission and the emission color cannot be seen by the naked eye, which is consistent with the black color of the sample. Similar to red emission, this infrared emission can be attributed to recombination between indium donor and deep-lying acceptors, such as Y band, which usually appear in wide bandgap semiconductors. , The Y band is related to the lattice imperfection, structure defects, and dislocation, and locates at about 170−270 meV above the valence band. − Here the In(III) may be the dominant acceptor. The optical characteristics of the Y band strongly depend on the impurity density and growth conditions.…”

Section: Resultsmentioning

confidence: 96%

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Structure and Photoluminescence of Pure and Indium-Doped ZnTe Microstructures

et al. 2011

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High-purity and doped ZnTe microstructures were synthesized with a single thermal evaporation method. The morphology of doped ZnTe microstructures shows multilayered periodical structure, which is due to the incorporation of In elements. The PL investigation demonstrated that the pure ZnTe microstructures emit only green light (close to the bandedge) while ZnTe doped with varied In concentrations emit red or infrared light without band-edge emission. These emission changes reflected that the Donor-Acceptor pair state transition can be tuned in semiconductor microstructures for future applications.

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Section: Resultsmentioning

confidence: 96%

“…32,33 The Y band is related to the lattice imperfection, structure defects, and dislocation, and locates at about 170-270 meV above the valence band. [34][35][36] Here the In(III) may be the dominant acceptor. The optical characteristics of the Y band strongly depend on the impurity density and growth conditions.…”

Section: Xrd Of As-preparedmentioning

confidence: 99%

Structure and Photoluminescence of Pure and Indium-Doped ZnTe Microstructures

et al. 2011

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“…We propose that charges are trapped at a range of states with energies spanning from midgap to close to the valence band. Transient absorption spectroscopy using a UV/vis probe provides limited information on the chemical nature of such trap sites; however, past studies using chemically sensitive probes have also noted a range of states with those close to the VB being proposed to be related to the presence of Zn vacancies and/or impurity defects, − while midgap states related to isolated oxygen present on the metalloid sublattice and also Zn vacancies are also reported. − On the basis of our spectroelectrochemcial studies, we are able to assign the dominant spectral feature observed in the visible region during TA studies of a ZnTe photoelectrode to deeply trapped photoelectrons. Following the relaxation of electrons in these trap or mid-bandgap states (ca.…”

Section: Discussionmentioning

confidence: 75%

Time-Resolved Spectroscopy of ZnTe Photocathodes for Solar Fuel Production

et al. 2017

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The negative conduction band potential and small bandgap of ZnTe make the material a promising photoelectrode for solar fuels production, photocatalyst, and solar cell component. However, the factors controlling the underlying efficiencies of the light-driven processes on ZnTe are not well understood. Here we report a combined spectroelectrochemical and transient absorption (TA) spectroscopic investigation of ZnTe photoelectrodes for CO2 reduction. In the visible region TA spectra are dominated by a broad positive photoinduced absorption at 540 nm following initial charge carrier relaxation (<540 nm). The 540 nm spectral feature is shown to be related to deeply trapped photoelectrons with charge carrier recombination occurring via a trapping–detrapping model on the microsecond time scale. Significantly these deeply trapped electrons are insensitive to the presence of electron acceptors and to the applied potential of the ZnTe electrode. Trapping at such states is proposed to be a significant factor limiting the photoelectrochemical activity of ZnTe. Near-IR spectral features associated with shallow trapped/conduction band electrons exist at >1150 nm. Shallow trapped electrons are generated and accumulate at potentials where photoelectrochemical H2 evolution and CO2 reduction occur, and we show these charges are able to undergo interfacial electron transfer to an acceptor molecule. The passivation of sites related to deep traps is proposed to be the key to optimize the photocatalytic and photoelectrochemical performance of ZnTe.

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“…The last mentioned effect can be due to light scattering at defect inclusions containing Er atoms. The appearance of complex absorption bands at $3-4 lm in ZnSe doped with Fe was reported in [16]. It is known, iron incorporate as substitutional impurity center of the 3d 6 electronic configuration in lattice of A II B VI compounds.…”

Section: Ir-spectroscopymentioning

confidence: 95%