Optical Pump–Terahertz Probe Study of HR GaAs:Cr and SI GaAs:EL2 Structures with Long Charge Carrier Lifetimes

Колесникова, Ирина Аполлоновна; Kobtsev, D. A.; Redkin, R. A.; Voevodin, Vladimir; Tyazhev, A.; Толбанов, О. П.; Sarkisov, Yury S.; Sarkisov, S. Yu.; Atuchin, Victor V.

doi:10.3390/photonics8120575

Cited by 6 publications

(5 citation statements)

References 23 publications

(47 reference statements)

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“…Therefore, local heating of the samples under the photoexcitation pulse occurred. In our previous study [19], we measured the temperature of GaAs slabs under similar photoexcitation conditions employing a thermocouple, and the measured surface temperature did not exceed the room temperature by more than 50 • C. The increased temperature definitely influences the charge carrier concentration, the scattering and recombination rates. For example, the SRH recombination rate is proportional to the thermal velocity of holes and electrons (see, for example, Supplementary Materials to Ref.…”

Section: Optical Pump-terahertz Probe Measurementsmentioning

confidence: 89%

“…For example, the SRH recombination rate is proportional to the thermal velocity of holes and electrons (see, for example, Supplementary Materials to Ref. [19]). The thermal velocities scale as square root of the temperature.…”

Section: Optical Pump-terahertz Probe Measurementsmentioning

confidence: 99%

“…The OPTP technique provides these possibilities. In our previous study, this technique was used to investigate another material for ionizing radiation and high-energy particle detectors, namely HR GaAs:Cr [19]. Previously, the OPTP technique with above-band-gap photoexcitation was applied to study 6H-SiC [20].…”

Section: Introductionmentioning

confidence: 99%

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Electrical Relaxation and Transport Properties of ZnGeP2 and 4H-SiC Crystals Measured with Terahertz Spectroscopy

et al. 2023

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Terahertz photoconductivity and charge carrier recombination dynamics at two-photon (ZnGeP2) and three-photon (4H-SiC) excitation were studied. Thermally annealed, high-energy electron-irradiated and Sc-doped ZnGeP2 crystals were tested. The terahertz charge carrier mobilities were extracted from both the differential terahertz transmission at a specified photoexcitation condition and the Drude–Smith fitting of the photoconductivity spectra. The determined terahertz charge carrier mobility values are ~453 cm2/V·s for 4H-SiC and ~37 cm2/V·s for ZnGeP2 crystals. The charge carrier lifetimes and the contributions from various recombination mechanisms were determined at different injection levels using the model, which takes into account the influence of bulk and surface Shockley–Read–Hall (SRH) recombination, interband radiative transitions and interband and trap-assisted Auger recombination. It was found that ZnGeP2 possesses short charge carrier lifetimes (a~0.01 ps−1, b~6 × 10−19 cm3·ps−1 and c~7 × 10−40 cm6·ps−1) compared with 4H-SiC (a~0.001 ps−1, b~3 × 10−18 cm3·ps−1 and c~2 × 10−36 cm6·ps−1), i.e., τ~100 ps and τ~1 ns at the limit of relatively low injection, when the contribution from Auger and interband radiative recombination is small. The thermal annealing of as-grown ZnGeP2 crystals and the electron irradiation reduced the charge carrier lifetime, while their doping with 0.01 mass % of Sc increased the charger carrier lifetime and reduced mobility. It was found that the dark terahertz complex conductivity of the measured crystals is not fitted by the Drude–Smith model with reasonable parameters, while their terahertz photoconductivity can be fitted with acceptable accuracy.

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Section: Optical Pump-terahertz Probe Measurementsmentioning

confidence: 89%

Section: Optical Pump-terahertz Probe Measurementsmentioning

confidence: 99%

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Electrical Relaxation and Transport Properties of ZnGeP2 and 4H-SiC Crystals Measured with Terahertz Spectroscopy

et al. 2023

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“…The effective charge carrier lifetime dependence on the injection level was determined as [42,43]: The e-h pair concentrations on the front and the opposite surfaces of the sample differ within one order of magnitude, which we consider to be a uniform distribution; we used the values of ∆n averaged over distance from the surface from x = 0 to x = L in further calculations (Table 1).…”

Section: Optical Pump-terahertz Probe Measurementsmentioning

confidence: 99%

Optical Absorption, Photocarrier Recombination Dynamics and Terahertz Dielectric Properties of Electron-Irradiated GaSe Crystals

Bereznaya,

Redkin,

Brudnyi

et al. 2023

Crystals

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Optical absorption spectra of 9 MeV electron-irradiated GaSe crystals were studied. Two absorption bands with the low-photon-energy threshold at 1.35 and 1.73 eV (T = 300 K) appeared in the transparency region of GaSe after the high-energy-electron irradiation. The observed absorption bands were attributed to the defect states induced by Ga vacancies in two charge states, having the energy positions at 0.23 and 0.61 eV above the valence band maximum at T = 300 K. The optical pump-terahertz probe technique (OPTP) was employed to study the dark and photoexcited terahertz conductivity and charge carrier recombination dynamics at two-photon excitation of as-grown and 9 MeV electron-irradiated GaSe crystals. The measured values of the differential terahertz transmission at a specified photoexcitation condition were used to extract the terahertz charge carrier mobilities. The determined terahertz charge carrier mobility values were ~46 cm2/V·s and ~14 cm2/V·s for as-grown and heavily electron-irradiated GaSe crystals, respectively. These are quite close to the values determined from the Lorentz–Drude–Smith fitting of the measured dielectric constant spectra. The photo-injection-level-dependent charge carrier lifetimes were determined from the measured OPTP data, bearing in mind the model injection-level dependencies of the recombination rates governed by interband and trap-assisted Auger recombination, bulk and surface Shockley–Read–Hall (SRH) recombination and interband radiative transitions in the limit of a high injection level. It was found that GaSe possesses a long charge carrier lifetime (a~1.9 × 10−6 ps−1, b~2.7 × 10−21 cm3ps−1 and c~1.3 × 10−37 cm6ps−1), i.e., τ~0.53 μs in the limit of a relatively low injection, when the contribution from SRH recombination is dominant. The electron irradiation of as-grown GaSe crystals reduced the charge carrier lifetime at a high injection level due to Auger recombination through radiation-induced defects. It was found that the terahertz spectra of the dielectric constants of as-grown and electron-irradiated GaSe crystals can be fitted with acceptable accuracy using the Lorentz model with the Drude–Smith term accounting for the free-carrier conductivity.

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“…Numerous techniques have been applied to improve the photodetection performances and usability of Bi 2 S 3 -based photodetectors, including vacancy-engineered photodetection [17], broadband photodetection (300-1000 nm) [22], electrolyte-assisted photodetection enhancement [18], flexible photodetectors [20], localized surface plasmon resonance assisted photodetection enhancement [23], infrared wavelength assisted enhancement [24] and Schottky barrier height assisted enhancement [22]. Doping can also be used to alter or enhance the physical properties of semiconducting host matrix [25][26][27]. There are several reports of the bismuth sulfide nanoparticles doped with transition metals, for example, Manganese (Mn 2+ ) doped Bi 2 S 3 nanoparticles with multiple morphologies were described by Anasane and Ameta [28].…”

Section: Introductionmentioning

confidence: 99%

Photodetecting properties on Sn-doped Bi₂S₃ thin film fabricated by nebulizer spray pyrolysis technique

Ganesh¹,

AlAbdulaal²,

Yahia³

2023

Phys. Scr.

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Metal chalcogenides have recently gained intensive attention due to their tunable bandgap energy, optoelectronic characteristics, and exceptional optical absorption. Because of the potential advantage of photodetectors, photovoltaic, holographic recording systems, and field-effect transistors, bismuth tri-sulfide (Bi2S3) crystals, in particular, have attracted a lot of focus in scientific research. In this study, the low-cost nebulizer spray technique was employed to synthesize the proposed Bi2S3:Sn thin films on glass substrates, varying the Sn doping concentrations in Bi2S3 films (from 1 to 3%). The crystallites of the orthorhombic-structured polycrystalline Bi2S3 films were all oriented in the same direction (130). According to the XRD spectra, preferred orientation and crystalline quality were improved by Sn doping concentrations up to 2%, but, above 2% of the Sn doping ratio, the structural properties were decreased. With increasing Sn-doping levels, the estimated direct band gap (Eg) of the Bi2S3:Sn films decreased, reaching a low value of 2.01 eV at 2% Sn and then rising. A field emission scanning electron microscope (FESEM) was applied to determine the size and shape of the grains in prepared Sn: Bi2S3 films.The 2% Sn-doped Bi2S3 thin film may be more appropriate for high-speed optoelectronic devices due to its high responsivity (1.24 AW-1), external quantum efficiency (40%), and detectivity properties (1.83×1010Jones). A potential mechanism for photodetector performance in the presence of air and UV radiation was also discussed in the present work for the proposed Sn: Bi2S3 thin films.

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Optical Pump–Terahertz Probe Study of HR GaAs:Cr and SI GaAs:EL2 Structures with Long Charge Carrier Lifetimes

Cited by 6 publications

References 23 publications

Electrical Relaxation and Transport Properties of ZnGeP2 and 4H-SiC Crystals Measured with Terahertz Spectroscopy

Electrical Relaxation and Transport Properties of ZnGeP2 and 4H-SiC Crystals Measured with Terahertz Spectroscopy

Optical Absorption, Photocarrier Recombination Dynamics and Terahertz Dielectric Properties of Electron-Irradiated GaSe Crystals

Photodetecting properties on Sn-doped Bi₂S₃ thin film fabricated by nebulizer spray pyrolysis technique

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Optical Pump–Terahertz Probe Study of HR GaAs:Cr and SI GaAs:EL2 Structures with Long Charge Carrier Lifetimes

Cited by 6 publications

References 23 publications

Electrical Relaxation and Transport Properties of ZnGeP2 and 4H-SiC Crystals Measured with Terahertz Spectroscopy

Electrical Relaxation and Transport Properties of ZnGeP2 and 4H-SiC Crystals Measured with Terahertz Spectroscopy

Optical Absorption, Photocarrier Recombination Dynamics and Terahertz Dielectric Properties of Electron-Irradiated GaSe Crystals

Photodetecting properties on Sn-doped Bi2S3 thin film fabricated by nebulizer spray pyrolysis technique

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Product

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Photodetecting properties on Sn-doped Bi₂S₃ thin film fabricated by nebulizer spray pyrolysis technique