title: Surface-state dependent optical properties of OH-, F-, and H-terminated 4H-SiC quantum dots.
abstract: Density functional calculations are performed for OH-, F- and H-terminated 4H-SiC 10-20 Å diameter clusters to investigate the effect of surface species upon the optical absorption properties. H-termination results in a pronounced size-dependent quantum-confinement in the absorption, whereas F- and OH-terminations exhibit much reduced size dependent absorption due to surface states. Our findings are in good agreement with recent experimental studies, and are able to explain the little explored dual-feature photoluminescence spectra of SiC quantum dots. We propose that along with controlling the size, suitable surface termination is the key for optimizing optical properties of 4H-SiC quantum structures, such as might be exploited in optoelectronics, photovoltaics and biological applications.
authors.affiliation: School of Electrical and Electronic Engineering, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK. m.m.b.m.rashid@ncl.ac.uk and School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia.
authors.forename: Marzaini
authors.initials: M
authors.lastname: Rashid
authors.affiliation: School of Electrical and Electronic Engineering, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK. m.m.b.m.rashid@ncl.ac.uk.
authors.forename: Amit K
authors.initials: AK
authors.lastname: Tiwari
authors.affiliation: School of Electrical and Electronic Engineering, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK. m.m.b.m.rashid@ncl.ac.uk.
authors.forename: J P
authors.initials: JP
authors.lastname: Goss
authors.affiliation: School of Electrical and Electronic Engineering, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK. m.m.b.m.rashid@ncl.ac.uk.
authors.forename: M J
authors.initials: MJ
authors.lastname: Rayson
authors.affiliation: School of Electrical and Electronic Engineering, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK. m.m.b.m.rashid@ncl.ac.uk.
authors.forename: P R
authors.initials: PR
authors.lastname: Briddon
authors.affiliation: School of Electrical and Electronic Engineering, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK. m.m.b.m.rashid@ncl.ac.uk.
authors.forename: A B
authors.initials: AB
authors.lastname: Horsfall