The Raman scattering in hafnium disulfide

Cingolani, A.; Lugarà, M.; Scamarcio, Gaetano; Lévy, F.

doi:10.1016/0038-1098(87)91126-4

Cited by 17 publications

(23 citation statements)

References 8 publications

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“…The experimental frequency of the A 1g mode of pristine multi-layer HfS 2 is found to be 336.1 ± 0.01 cm −1 from the measurements reported in Supplementary Fig. 1c,d , in good agreement with the literature 24 . The deviation of the measured peak from this value demonstrates the presence of compressive and tensile strain along the device (green arrows in Fig.…”

Section: Resultssupporting

confidence: 89%

Strain-engineered inverse charge-funnelling in layered semiconductors

et al. 2018

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The control of charges in a circuit due to an external electric field is ubiquitous to the exchange, storage and manipulation of information in a wide range of applications. Conversely, the ability to grow clean interfaces between materials has been a stepping stone for engineering built-in electric fields largely exploited in modern photovoltaics and opto-electronics. The emergence of atomically thin semiconductors is now enabling new ways to attain electric fields and unveil novel charge transport mechanisms. Here, we report the first direct electrical observation of the inverse charge-funnel effect enabled by deterministic and spatially resolved strain-induced electric fields in a thin sheet of HfS2. We demonstrate that charges driven by these spatially varying electric fields in the channel of a phototransistor lead to a 350% enhancement in the responsivity. These findings could enable the informed design of highly efficient photovoltaic cells.

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Section: Resultssupporting

confidence: 89%

Strain-engineered inverse charge-funnelling in layered semiconductors

et al. 2018

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“…Note that two dimensional materials have abnormal structural, electronic and electro-optical properties [24][25][26]. Note that two dimensional materials have abnormal structural, electronic and electro-optical properties [24][25][26].…”

Section: Introductionmentioning

confidence: 99%

2D-HfS₂as an efficient photocatalyst for water splitting

Singh

Gupta

Sonvane

et al. 2016

Catal. Sci. Technol.

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Two dimensional monolayer nanostructures for water splitting solar photocatalyst are drawing more attention due to their extraordinary properties. Using the first principles calculations we have systematically investigate the structural, electronic and vibrational properties of the corresponding HfS 2 monolayer in both phases of hexagonal (1H) and trigonal (1T). The most stable adsorption configurations and adsorption energies are calculated. The adsorption energy of H 2 O on the substrate is 646.53 kJ/mol for 1H-phase and 621.65 kJ/mol for 1T-phase of HfS 2 . It shows that H 2 O molecule has higher interaction with the HfS 2 substrate. The calculated redox potentials of H 2 O splitting are properly astride by the valence and conduction bands suggesting monolayer of 1H and 1T-HfS 2 shows same characteristic as a photocatalyst for water splitting.Further we have also calculated obtained optical band gap for 1H and 1T phases of HfS 2 is 2.60 eV and 3.10 eV, respectively. We have also calculated Raman spectrum signatures of the monolayer 1H and 1T-phase of in -plane vibrational mode of the Hf and S atoms (E 1g ) and the out-of-plane vibrational mode of S atoms (A 1g and A 2u ). Our works suggest a lot more research and attention in this field needed for their practical application as a visible light active photocatalysts.

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“…The weak peaks observed at approximately 256.2 cm −1 were due to the E g mode, which resulted from the in-plane out-of-phase vibrations of the atomic planes of S. The intense peaks observed at approximately 335.3 cm −1 were due to the A 1 g mode, which resulted from the out-of-plane out-of-phase vibrations of the atomic planes of S [ 21 , 52 , 53 , 54 , 55 ]. The E g and A 1g peaks are the two most commonly observed signals in 1T HfS 2 crystals [ 21 , 27 , 53 , 55 , 56 , 57 , 58 , 59 , 60 ]. Figure 1 e indicates that the grown HfS 2 crystals were in the 1T phase.…”

Section: Resultsmentioning

confidence: 99%

Influence of Mn, Fe, Co, and Cu Doping on the Photoelectric Properties of 1T HfS2 Crystals

et al. 2021

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Doping plays a vital role in the application of transition-metal dichalcogenides (TMDCs) because it can increase the functionality of TMDCs by tuning their native characteristics. In this study, the influence of Mn, Fe, Co, and Cu doping on the photoelectric properties of HfS2 was investigated. Pristine, Mn-, Fe-, Co-, and Cu-doped HfS2 crystals were grown using the chemical vapor transport method. Scanning electron microscopy images showed that the crystals were layered and transmission electron microscopy, X-ray diffraction, and Raman spectroscopy measurements confirmed that the crystals were in the 1T-phase with a CdI2-like structure. The bandgap of pristine HfS2 obtained from the absorption and photoconductivity spectra was approximately 1.99 eV. As the dopant changed from Mn, Fe, and Co, to Cu, the bandgap gradually increased. The activation energies of the samples were determined using temperature-dependent current-voltage curves. After doping, the activation energy decreased, and the Co-doped HfS2 exhibited the smallest activation energy. Time-resolved photoresponse measurements showed that doping improved the response of HfS2 to light; the Co-doped HfS2 exhibited the best response. The photoresponsivity of HfS2 as a function of the laser power and bias voltage was measured. After doping, the photoresponsivity increased markedly; the Co-doped HfS2 exhibited the highest photoresponsivity. All the experimental results indicated that doping with Mn, Fe, Co, and Cu significantly improved the photoresponsive performance of HfS2, of which Co-doped HfS2 had the best performance.

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The Raman scattering in hafnium disulfide

Cited by 17 publications

References 8 publications

Strain-engineered inverse charge-funnelling in layered semiconductors

Strain-engineered inverse charge-funnelling in layered semiconductors

2D-HfS₂as an efficient photocatalyst for water splitting

Influence of Mn, Fe, Co, and Cu Doping on the Photoelectric Properties of 1T HfS2 Crystals

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The Raman scattering in hafnium disulfide

Cited by 17 publications

References 8 publications

Strain-engineered inverse charge-funnelling in layered semiconductors

Strain-engineered inverse charge-funnelling in layered semiconductors

2D-HfS2as an efficient photocatalyst for water splitting

Influence of Mn, Fe, Co, and Cu Doping on the Photoelectric Properties of 1T HfS2 Crystals

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2D-HfS₂as an efficient photocatalyst for water splitting