Direct and quasi-direct band gap silicon allotropes with remarkable stability

Abstract

In our present work, five previously proposed sp${}^3$ carbon crystals were suggested as silicon allotropes and their stabilities, electronic and optical properties were investigated by first-principles method. We find that these allotropes with direct or quasi-direct band gaps in range of 1.2-1.6 eV are very suitable for applications in thin-film solar cells. They display strong adsorption coefficients in the visible range of the sunlight in comparison with diamond silicon. These five silicon allotropes are confirmed possessing positive dynamical stability and remarkable themodynamical stability close to that of diamond silicon. Especially, the direct band gap M585-silicon possessing energy higher than diamond silicon only 25 meV per atom is expected to be experimentally produced for thin-film solar cells.

5 pages, 5 figures and 1 table

References in corpus (4)

• Superconductive "sodalite"-like clathrate calcium hydride at high pressures
• Towards Direct-Gap Silicon Phases by the Inverse Band Structure Design Approach
• New Superhard Carbon Phases Between Graphite and Diamond
• Four superhard carbon allotropes: First-principle study

Cited by in corpus (4)

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• Prediction of new sp3 silicon and germanium allotropes from the topology-based multiscale method
• Formation of Micrometer-Sized Textured Hexagonal Silicon Crystals via Nanoindentation