Abstract
Using first-principles calculations, we have investigated the evolution of band edges in few-layer phosphorene as a function of the number of P layers. Our results predict that monolayer phosphorene is an indirect band gap semiconductor and its valence band edge is extremely sensitive to strain. Its band gap could undergo an indirect-to-direct transition under a lattice expansion as small as 1% along the zigzag direction. A semiempirical interlayer coupling model is proposed, which can reproduce the evolution of valence band edges obtained by first-principles calculations well. We conclude that the interlayer coupling plays a dominant role in the evolution of the band edges via decreasing both band gap and carrier effective masses with the increase of phosphorene thickness. Scrutiny of the orbital-decomposed band structure provides a better understanding of the upward shift of the valence band maximum, surpassing that of the conduction band minimum.
Original language | English |
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Pages (from-to) | 4876-4883 |
Number of pages | 8 |
Journal | Journal of Physical Chemistry Letters |
Volume | 6 |
Issue number | 24 |
DOIs | |
Publication status | Published - 2015 Dec 17 |
Keywords
- first-principles calculations
- orbital-decomposed band structure
- phosphorene
- semiempirical interlayer coupling
ASJC Scopus subject areas
- Materials Science(all)
- Physical and Theoretical Chemistry