Transition between direct and indirect band gap in silicon nanocrystals
2013 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 87, no 24, 245401- p.Article in journal (Refereed) Published
Using ground-state density functional theory we study the transition from indirect to direct band gap in hydrogen-terminated silicon nanocrystals (NCs) as a function of decreasing diameter. The studied range, from 1.0 to 4.6 nm diameter of nanocrystals, with spherical and Wulff-shape NCs, covers the transition from nano-to bulk regime. A change in the symmetry of the lowest unoccupied state as a function of decreasing NC diameter is observed, gradually increasing the oscillator strength of transitions from the highest occupied to the lowest unoccupied state. Real space and Fourier space characteristics of highest occupied and lowest unoccupied states are explored in detail and linked to a smooth transition from nano-to bulk regime.
Place, publisher, year, edition, pages
2013. Vol. 87, no 24, 245401- p.
IdentifiersURN: urn:nbn:se:uu:diva-203530DOI: 10.1103/PhysRevB.87.245401ISI: 000319909600003OAI: oai:DiVA.org:uu-203530DiVA: diva2:637145