Temperature dependence of the indirect bandgap in thallium bromide from cathodoluminescence spectroscopy

Ray, Anjana; Smith, Holland M.; Haegel, N. M.

doi:10.1063/1.4874265

Cited by 6 publications

(3 citation statements)

References 25 publications

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“…The phonon polaritons have longer propagation lengths and lifetimes. Specifically, surface phonon polaritons (SPhPs) supported on polar crystals, [38] such as SiC, [39] h-BN [40] and TlBr, [41] have inherent long lifetimes (∼1 ps) and low optical loss, [31] but surface plasmon polaritons (SPPs) in metals, which are lossy with a lifetime of ∼10 fs. [42] Confinement factors (β = λ 0 /λ p , defined as the ratio of free space photon propagation wavelength to polariton wavelength) of over 40 have been achieved for both h-BN phonon polaritons, [43] which means that infrared wave (5-20 µm) can be modulated with wavelength down to a few hundreds of nanometers.…”

Section: Introductionmentioning

confidence: 99%

Narrowband perfect terahertz absorber based on polar-dielectrics metasurface*

Zhao

Zhou

et al. 2020

Chinese Phys. B

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We theoretically propose a narrowband perfect absorber metasurface (PAMS) based on surface phonon polaritons in the terahertz range. The PAMS has unit cell consisting of a silver biarc on the top, a thin polar-dielectric in the middle and a silver layer at the bottom. The phonon polaritons are excited at the interface between the silver biarc and the polar dielectric, and enhance the absorption of the PAMS. The absorption peak is at 36.813 μm and the full width half maximum (FWHM) is nearly 36 nm, independent of the polarization and incidence angle. The electric fields are located at the split of the biarc silver layer and the quality factor Q is 1150. The FWHM decreases with the decreasing split width. When the thickness of the bottom layer is larger than 50 nm, the narrow band and high absorption are insensitive to the thickness of those layers. The designed absorber may have useful applications in terahertz spectra such as energy harvesting, thermal emitter, and sensing.

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Section: Introductionmentioning

confidence: 99%

Narrowband perfect terahertz absorber based on polar-dielectrics metasurface*

Zhao

Zhou

et al. 2020

Chinese Phys. B

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“…23,24) Some researchers have also reported the emission properties induced by X-ray or electron beam irradiations. [25][26][27] Various luminescence bands have been observed and are tentatively attributed to free or bound excitons or electronic transitions at localized centers such as defects or impurities.…”

Section: Introductionmentioning

confidence: 99%

Photoluminescence and scintillation of TlBr crystals at low temperatures

Koshimizu

Hitomi

Nogami

et al. 2019

Jpn. J. Appl. Phys.

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The photoluminescence and X-ray-induced radioluminescence properties of TlBr crystals were analyzed. We compared the samples cut from two parts of the crystal that are empirically known to be appropriate and inappropriate for semiconductor detectors. In the X-ray-induced radioluminescence spectra, two bands were observed at 490 and 650 nm for both the samples. We observed an additional band at 560 nm only for the inappropriate part of the crystal. We observed an emission band at 520 nm in the photoluminescence spectra of both the samples and attributed this to some defects near the surface on which photoexcitation occurs. Interestingly, an emission band at 560 nm appeared after thermal cycle from room temperature to 5 K and back to room temperature. Assuming that the thermal cycle introduced some distortions in the sample, the emission band at 560 nm could be related to lattice defects, such as dislocation, that are relevant to distortion.

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“…Several studies on the preparation of TlBr detectors have been carried out and improvements in the methodology of purification, growth, and characterization of the crystals have been described, aiming to achieve all these factors [2][3][4][5][6][7]. However, as it can be observed in the literature [1,[8][9][10][11][12], the TlBr detector limitations are not yet completely resolved: primarily, the low collection efficiency of charge carriers, a fact that is probably caused by impurities and defects created in the crystal growth or in the surface treatment process. There is a consensus in the literature that the TlBr crystal purity is a crucial factor for its optimal performance as a radiation detector [2][3][4][5][6].…”

Section: Introductionmentioning

confidence: 99%

Influence of Impurities on the Radiation Response of the TlBr Semiconductor Crystal

Santos¹,

Mesquita²,

Silva³

et al. 2017

Advances in Materials Science and Engineering

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Two commercially available TlBr salts were used as the raw material for crystal growths to be used as radiation detectors. Previously, TlBr salts were purified once, twice, and three times by the repeated Bridgman method. The purification efficiency was evaluated by inductively coupled plasma mass spectroscopy (ICP-MS), after each purification process. A compartmental model was proposed to fit the impurity concentration as a function of the repetition number of the Bridgman growths, as well as determine the segregation coefficients of impurities in the crystals. The crystalline structure, the stoichiometry, and the surface morphology of the crystals were evaluated, systematically, for the crystals grown with different purification numbers. To evaluate the crystal as a radiation semiconductor detector, measurements of its resistivity and gamma-ray spectroscopy were carried out, using 241Am and 133Ba sources. A significant improvement of the radiation response was observed in function of the crystal purity.

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Temperature dependence of the indirect bandgap in thallium bromide from cathodoluminescence spectroscopy

Abstract: Articles you may be interested inTemperature dependence of exciton-surface plasmon polariton coupling in Ag, Au, and Al films on InxGa1−xN/GaN quantum wells studied with time-resolved cathodoluminescence

Cited by 6 publications

References 25 publications

Narrowband perfect terahertz absorber based on polar-dielectrics metasurface*

Narrowband perfect terahertz absorber based on polar-dielectrics metasurface*

Photoluminescence and scintillation of TlBr crystals at low temperatures

Influence of Impurities on the Radiation Response of the TlBr Semiconductor Crystal

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