Vibrational properties of silicene and germanene

Scalise, Emilio; Houssa, Michel; Pourtois, Geoffrey; Broek, Bas van den; Afanas’ev, Valery V.; Stesmans, André

doi:10.1007/s12274-012-0277-3

Cited by 208 publications

(235 citation statements)

References 35 publications

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“…From Table 1, lattice constant, nearest neighbor distance, and height of buckled, which are indicated by a, d, and h letters, respectively, are compared with other references and found that our calculations are in agreement with them [14][15][16]. The energy of the pristine silicene with low buckling structure is the lowest and thus low buckling is the most stable structure.…”

Section: Resultssupporting

confidence: 74%

The study of electronic structure and properties of silicene for gas sensor application

Wella

Syaputra

Wungu

et al. 2016

AIP Conference Proceedings

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Section: Resultssupporting

confidence: 74%

The study of electronic structure and properties of silicene for gas sensor application

Wella

Syaputra

Wungu

et al. 2016

AIP Conference Proceedings

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“…Raman spectroscopy is a widely used experimental technique to identify the characteristic vibrational modes of materials. It is one of the most commonly used optical techniques for the characterization of 2D materials [36]. Several properties can be determined from analysis of the Raman spectra.…”

Section: Resultsmentioning

confidence: 99%

Structural and electronic properties of atomically thin germanium selenide polymorphs

et al. 2015

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tronic counterpart to the layered group V semiconductors [25]. Similarly, GeSe is an isoelectronic counterpart to the group V semiconductors and has the same layered structures. α-GeSe nanosheets have been synthesized by several methods and applied in photodetector devices [11,12]. The semiconducting electronic properties of α-GeSe have been confirmed by a recent theoretical investigation [26]. However, the stability and electronic properties of the GeSe monolayers in the other polymorphs have not been investigated. A systematic theoretical investigation of their structures and properties will not only enrich our understanding of the property variations of the polymorphs, but it will also facilitate potential applications. Despite some theoretical and experimental studies of α-GeSe being reported, many important questions still remain unknown: what are the stabilities of the GeSe monolayers in the different phases? How do the electronic properties vary with the different phase structures? In this work, we aim to answer these questions.In this work, by comprehensive density functional theory (DFT) calculations, we report the discovery of the four previously unknown phases of the GeSe monolayer in addition to layered α-GeSe: β-GeSe, γ-GeSe, δ-GeSe, and ε-GeSe. The five polymorphs of GeSe exhibit versatile energy band gaps, which are very significant for broadband optoelectronic and photonic applications. In particular, β-GeSe is an indirect band-gap semiconductor with a band gap of 3.01 eV calculated using the HSE06 exchange-correlation functional. From the band edge alignment, the conduction band minimum (CBM) and valence band maximum (VBM) energies of β-GeSe are −2.54 and −5.55 eV, respectively, which indicates that it is a promising material Using comprehensive density functional theory calculations, we systematically investigate the structure, stability, and electronic properties of five polymorphs of GeSe monolayer, and highlight the differences in their structural and electronic properties. Our calculations show that the five free-standing polymorphs of GeSe are stable semiconductors. β-GeSe, γ-GeSe, δ-GeSe, and ε-GeSe are indirect gap semiconductors, whereas α-GeSe is a direct gap semiconductor. We calculated Raman spectra and scanning tunneling microscopy images for the five polymorphs. Our results show that the β-GeSe monolaye r is a candidate for water splitting.

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“…According to published reports, a peak near 290 cm −1 corresponds to a "G-like" shift in the germanene layer. 22,24 Moreover, Maldonado et al studied Ge electrodeposition onto a surface enhanced Raman substrate (SERS-active Au) on which the self-limited amount of Ge had been deposited. In that study a peak at 290 cm −1 , at −1.2 V in a pH 9.2 Ge solution, was observed.…”

Section: Resultsmentioning

confidence: 99%

Electrochemical Formation of Germanene: pH 4.5

Ledina

Bui

Liang

et al. 2017

J. Electrochem. Soc.

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Germanene is a single layer allotrope of Ge, with a honeycomb structure similar to graphene. This report concerns the electrochemical formation of germanene in a pH 4.5 solution. The studies were performed using in situ Electrochemical Scanning Tunneling Microscopy (EC-STM), voltammetry, coulometry, surface X-ray diffraction (SXRD) and Raman spectroscopy to study germanene electrodeposition on Au(111) terraces. The deposition of Ge is kinetically slow and stops after 2–3 monolayers. EC-STM revealed a honeycomb (HC) structure with a rhombic unit cell, 0.44 ± 0.02 nm on a side, very close to that predicted for germanene in the literature. Ideally the HC structure is a continuous sheet, with six Ge atoms around each hole. However, only small domains, surrounded by defects, of this structure were observed in this study. The small coherence length and multiple rotations domains made direct observation with surface X-ray diffraction difficult. Raman spectroscopy was used to investigate the multi-layer Ge deposits. A peak near 290 cm−1, predicted to correspond to germanene, was observed on one particular area of the sample, while the rest resembled amorphous germanium. Electrochemical studies of germanene showed limited stability when exposed to oxygen.

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Vibrational properties of silicene and germanene

Cited by 208 publications

References 35 publications

The study of electronic structure and properties of silicene for gas sensor application

The study of electronic structure and properties of silicene for gas sensor application

Structural and electronic properties of atomically thin germanium selenide polymorphs

Electrochemical Formation of Germanene: pH 4.5

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