Lone pair driven anisotropy in antimony chalcogenide semiconductors

Wang, Xinwei; Li, Zhenzhu; Kavanagh, Seán R.; Ganose, Alex M.; Walsh, Aron

doi:10.1039/d1cp05373f

Cited by 40 publications

(71 citation statements)

References 93 publications

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“…Ribbon formation is driven by the Sb lone pair, with ribbons stacked together by weak interactions. 11 According to our previous optimization using the HSE06 hybrid functional and D3 dispersion correction, 11 the calculated lattice parameters are 3.80/3.95 Å, 11.20/11.55 Å, and 11.39/11.93 Å for Sb 2 S 3 /Sb 2 Se 3 along the a , b , and c axes, respectively. Sb 2 X 3 are indirect band gap semiconductors with calculated indirect/direct band gaps of 1.79/1.95 eV and 1.42/1.48 eV, respectively, which are in reasonable agreement with previous experimental 1 − 5 , 27 − 29 and theoretical studies.…”

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confidence: 99%

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Band versus Polaron: Charge Transport in Antimony Chalcogenides

et al. 2022

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Antimony sulfide (Sb 2 S 3 ) and selenide (Sb 2 Se 3 ) are emerging earth-abundant absorbers for photovoltaic applications. Solar cell performance depends strongly on charge-carrier transport properties, but these remain poorly understood in Sb 2 X 3 (X = S, Se). Here we report band-like transport in Sb 2 X 3 , determined by investigating the electron–lattice interaction and theoretical limits of carrier mobility using first-principles density functional theory and Boltzmann transport calculations. We demonstrate that transport in Sb 2 X 3 is governed by large polarons with moderate Fröhlich coupling constants (α ≈ 2), large polaron radii (extending over several unit cells), and high carrier mobility (an isotropic average of >10 cm 2 V –1 s –1 for both electrons and holes). The room-temperature mobility is intrinsically limited by scattering from polar phonon modes and is further reduced in highly defective samples. Our study confirms that the performance of Sb 2 X 3 solar cells is not limited by intrinsic self-trapping.

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confidence: 99%

“…31 − 35 However, neither the structural dimensionality nor the electronic dimensionality of Sb 2 X 3 is 1D. 11 , 36 …”

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Band versus Polaron: Charge Transport in Antimony Chalcogenides

et al. 2022

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“…CdTe and GaAs are tetrahedral semiconductors that adopt the zincblende structure (space group F 43m). Sb 2 Se 3 and Sb 2 S 3 are layered materials (space group P nma), composed of one-dimensional [Sb 4 X 6 ] n ribbons with covalent metalchalcogen bonds within each ribbon and van der Waals interactions between ribbons [60][61][62][63][64][65] . Beyond these covalently-bonded crystals, we also studied four metal oxides (In 2 O 3 , ZnO, CeO 2 , TiO 2 ).…”

Section: Defect Suitementioning

confidence: 99%

“…4). This remarkable ability to distort likely stems from their soft, quasi-1D structure [61] , with van der Waals voids between atomic chains [69] (SI Fig. S5).…”

Section: Rebondingmentioning

confidence: 99%

Identifying the ground state structures of point defects in solids

Mosquera‐Lois¹,

Kavanagh²,

Walsh³

et al. 2022

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Point defects are a universal feature of crystalline materials. Their identification is often addressed by combining experimental measurements with theoretical models. The standard approach of simulating defects is, however, prone to missing the ground state atomic configurations associated with energy-lowering reconstructions from the idealised crystallographic environment. Missed ground states compromise the accuracy of calculated properties. To address this issue, we report an approach to efficiently navigate the defect configurational landscape using targeted bond distortions and rattling. Application of our workflow to a range of materials (CdTe, GaAs, Sb2S3, Sb2Se3, CeO2, In2O3, ZnO, anatase-TiO2) reveals symmetry breaking in each host crystal that is not found via conventional local minimisation techniques. The point defect distortions are classified by the associated physico-chemical factors. We demonstrate the

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“…To cut a long story short, we found that the dimensionality depends on the property you're interested in. So it might be that you have particular structural dimensionality, but then the bond strength, dielectric functions, effective masses each have their own anisotropy 20 . But one point we thought would be of direct relevance to this community is the carrier mobility, which shows that the conduction pathways in Sb 2 X 3 can be classified as 2D or 3D depending on the composition and carrier type 21 .…”

Section: Novel Semiconductorsmentioning

confidence: 99%