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Exploration of photovoltaic materials has received enormous interest for a wide range of both fundamental and applied research. Therefore, in this work, we identify a CsSi compound with a Zintl phase as a promising candidate for photovoltaic material by using a global structure prediction method. Electronic structure calculations indicate that this phase possesses a quasi-direct band gap of 1.45 eV, suggesting that its optical properties could be superior to those of diamond-Si for capturing sunlight from the visible to the ultraviolet range. In addition, a novel silicon allotrope is obtained by removing Cs atoms from this CsSi compound. The superconducting critical temperature ( T c ) of this phase was estimated to be of 9 K in terms of a substantial density of states at the Fermi level. Our findings represent a new promising CsSi material for photovoltaic applications, as well as a potential precursor of a superconducting silicon allotrope.
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ScSI: A New Exfoliatable Semiconductor
ScSI, a missing member of the rare earth sulfoiodide (RESI) family of materials, has been synthesized for the first time. ScSI crystallizes in the FeOCl structure type, space group Pmmn (No. 59), a = 3.8904(2), b = 5.0732(9), c = 8.9574(6) Å. Both hyperspectral reflectance measurements and ab initio calculations support the presence of an indirect optical band gap of 2.0 eV. The bulk crystal is found to be readily exfoliatable, enabling its use as an optical component in novel heterostructures. The impact of lithium intercalation on its electronic band structure is also explored. A broader correlation is drawn between the observed structural trends in all known 1:1:1 sulfoiodide phases, cationic proportions, and electronic considerations. The realization of this phase both fills a significant synthetic gap in the literature and presents a novel exfoliatable phase for use as an optical component in next-generation heterostructure devices.
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- PAR ID:
- 10335520
- Date Published:
- Journal Name:
- Chemistry of Materials
- ISSN:
- 0897-4756
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.1021/acs.chemmater.2c00318
