Approximate quasiparticle correction for calculations of the energy gap in two-dimensional materials

Guilhon, Ivan; Koda, Daniel S.; Ferreira, L. G.; Marques, Marcelo; Teles, L. K.

doi:10.1103/physrevb.97.045426

Cited by 22 publications

(33 citation statements)

References 53 publications

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“…The DFT-1/2 band gaps have a good correspondence to GW calculations. As reported from several publications, − both methods have similar accuracy in predicting the experiment. In the case of rhombohedral CsGeI 3 , for which optical absorption measurements show a band gap of 1.63 eV, the DFT-1/2 method results in a slightly overestimated value of 1.80 eV.…”

Section: Resultssupporting

confidence: 70%

Tunable Band Gap and Rhombohedral Distortion in Lead-Free CsSn_1–xGe_xI₃ Mixed Perovskites

et al. 2021

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The absence of lead and also organic molecules in perovskites materials can be a good path to avoid toxicity and increase the stability of these high-potential compounds for photovoltaic applications. Particularly, a CsSnGeI3 alloy appears as a good alternative in this way, with initial evidence of improved properties. We provide a theoretical study that includes local strains, disorder effects, spin–orbit interactions, and approximated quasiparticle corrections via a DFT-1/2 method, delivering energy gaps in excellent agreement with experiments and state-of-art calculations. The alloy is stable in the entire composition range for usual growth temperatures, but a structural transition tendency happens between cubic and rhombohedral structures. Differently from tin–lead perovskite alloys, the fundamental energy band gap varies almost linearly with the composition, with very small bowing, an effect here explained in terms of statistics and average orbital characters. Our results increase the knowledge of the basic properties of this alloy and emphasize it as a promising material for solar-cell technology.

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Section: Resultssupporting

confidence: 70%

Tunable Band Gap and Rhombohedral Distortion in Lead-Free CsSn_1–xGe_xI₃ Mixed Perovskites

et al. 2021

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“…A previous publication assessing the application of DFT-1/2 quasiparticle correction to two-dimensional systems indicates that the success of the approximation is compound-dependent . Since this method is designed for correcting localized electronic states, a lower orbital mixing between B s and X p orbitals at the VBM results in better gap values.…”

Section: Resultsmentioning

confidence: 99%

Electronic Structure Panorama of Halide Perovskites: Approximated DFT-1/2 Quasiparticle and Relativistic Corrections

et al. 2020

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Halide perovskite compounds emerged recently as great candidates for efficient photovoltaics, although huge technical obstacles still have to be overcome. Additionally, their accurate theoretical description is difficult to be reached due to the high level of complexity of this class of materials. In this work, we provide a vast panorama of electronic properties, correlated with its relaxed internal geometry, for a group of 48 ABX3 cubic halide perovskites (A = CH3NH3, CH(NH2)2, Cs, Rb; B = Pb, Sn, Ge, Si; X = I, Br, Cl). Including the DFT-1/2 approximated quasiparticle and spin–orbit corrections, our model results in band gaps with an impressive agreement with experiments, comparable with the expensive state-of-the-art GW method. We provide trends in electronic properties depending on different atoms exchanged, concluding that 16 materials present band gaps more suitable for solar cell applications. Besides, the formation of BX3 units is observed in hybrid Sn, Ge, and Si perovskites, resulting from the distortion of the inorganic lattice. We elucidate the significant band gap broadening due to this segregation using orbital overlap considerations, which is consistent with previous experimental findings. Finally, the presented method establishes a reliable low-cost approach, being especially useful for more sophisticated perovskite systems as heterostructures, alloys, and low symmetric compounds.

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“…Recently, a variety of two dimensional (2D) materials have been extensively studied as the photocatalysts for water splitting, due to their large specific surface areas as well as the short charge migration distances, which could enhance the catalytic performance by hindering the electronhole recombination. [10][11][12][13][14][15] A typical example is monolayer SnS 2 , which 3 yielded a photocurrent density of 2.75 mA cm -2 at 1.0 V, nearly 72 times larger than that of bulk SnS 2 , proven in theory and experiment. 9 Other 2D materials such as transition metal dichalcogenides, 16 MXenes, 17 group-III monochalcogenides, 18 ternary zinc nitrides, 19,20 and MPSe 3 21 etc.…”

Section: Introductionmentioning

confidence: 96%

Two-dimensional silicon chalcogenides with high carrier mobility for photocatalytic water splitting

et al. 2019

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Highly-efficient water splitting based on solar energy is one of the most attractive research focuses in the energy field. Searching for more candidate photocatalysts that can work under visible-light irradiation are highly demanded. Herein, using first principle calculations based on density functional theory (DFT), we predict that the two dimensional silicon chalcogenides, i.e. SiX (X=S, Se, Te) monolayers, as semiconductors with 2.43 eV~3.00 eV band gaps, exhibit favorable band edge positions for photocatalytic water splitting. The optical adsorption spectra demonstrate that the SiX monolayers have pronounced optical absorption in the visible light region. Moreover, the band gaps and band 2 edge positions of silicon chalcogenides monolayers can be tuned by applying biaxial strain or increasing the number of layers, in order to better fit the redox potentials of water. The combined novel electronic, high carrier mobility, and optical properties render the two dimensional SiX a promising photocatalyst for water splitting.Recently, a variety of two dimensional (2D) materials have been extensively studied as the photocatalysts for water splitting, due to their large specific surface areas as well as the short charge migration distances, which could enhance the catalytic performance by hindering the electronhole recombination. 10-15 A typical example is monolayer SnS 2 , which 3 yielded a photocurrent density of 2.75 mA cm -2 at 1.0 V, nearly 72 times larger than that of bulk SnS 2 , proven in theory and experiment. 9 Other 2D materials such as transition metal dichalcogenides, 16 MXenes, 17 group-III monochalcogenides, 18 ternary zinc nitrides, 19,20 and MPSe 3 21 etc. have also been predicated theoretically for photocatalyst application.Moreover, the booming research advancements of the stabilities and electronic properties of group IV-VI monolayers, which are isoelectronic counterparts of group V such as phosphorene, have been reported in the last few years. [22][23][24][25][26][27][28][29][30][31][32] The group IV mono-chalcogenides MX (M= Si, Ge, Sn and X = S or Se), whose buckled honeycomb lattice is similar to that of black phosphorene, are also candidate materials for photocatalytic water splitting. Nevertheless, their calculated overpotentials for OER are quite large, or a specific basic or acidic condition is required to obtain good photocatalytic activity. 33 The monolayer germanium monochalcogenides, like blue phosphorene, was predicted as UV-light-driven photocatalyst, owing to the large band gap. 34 Therefore, it is highly worthwhile to further investigate the electronic and optical properties of other group IV-VI monolayers, for the sake of finding new candidate materials with improved properties for optoelectronic devices. Motivated by this conception, we have conducted a comprehensive investigation of the stability and electronic properties of silicon chalcogenides, i.e. SiX (X=S, Se and Te) monolayers, based on density 4 functional theory. It is found that the SiX monolayers are of high dynamic, m...

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Approximate quasiparticle correction for calculations of the energy gap in two-dimensional materials

Cited by 22 publications

References 53 publications

Tunable Band Gap and Rhombohedral Distortion in Lead-Free CsSn_1–xGe_xI₃ Mixed Perovskites

Tunable Band Gap and Rhombohedral Distortion in Lead-Free CsSn_1–xGe_xI₃ Mixed Perovskites

Electronic Structure Panorama of Halide Perovskites: Approximated DFT-1/2 Quasiparticle and Relativistic Corrections

Two-dimensional silicon chalcogenides with high carrier mobility for photocatalytic water splitting

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Approximate quasiparticle correction for calculations of the energy gap in two-dimensional materials

Cited by 22 publications

References 53 publications

Tunable Band Gap and Rhombohedral Distortion in Lead-Free CsSn1–xGexI3 Mixed Perovskites

Tunable Band Gap and Rhombohedral Distortion in Lead-Free CsSn1–xGexI3 Mixed Perovskites

Electronic Structure Panorama of Halide Perovskites: Approximated DFT-1/2 Quasiparticle and Relativistic Corrections

Two-dimensional silicon chalcogenides with high carrier mobility for photocatalytic water splitting

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Tunable Band Gap and Rhombohedral Distortion in Lead-Free CsSn_1–xGe_xI₃ Mixed Perovskites

Tunable Band Gap and Rhombohedral Distortion in Lead-Free CsSn_1–xGe_xI₃ Mixed Perovskites