title: Improved infrared photoluminescence characteristics from circularly ordered self-assembled Ge islands.
abstract: The formation of circularly ordered Ge-islands on Si(001) has been achieved because of nonuniform strain field around the periphery of the holes patterned by focused ion beam in combination with a self-assembled growth using molecular beam epitaxy. The photoluminescence (PL) spectra obtained from patterned areas (i.e., ordered islands) show a significant signal enhancement, which sustained till 200 K, without any vertical stacking of islands. The origin of two activation energies in temperature-dependent PL spectra of the ordered islands has been explained in detail.
authors.affiliation: Department of Physics and Meteorology, Indian Institute of Technology Kharagpur, Kharagpur 721302, India. physkr@phy.iitkgp.ernet.in.
authors.forename: Samaresh
authors.initials: S
authors.lastname: Das
authors.forename: Kaustuv
authors.initials: K
authors.lastname: Das
authors.forename: Raj Kumar
authors.initials: RK
authors.lastname: Singha
authors.forename: Santanu
authors.initials: S
authors.lastname: Manna
authors.forename: Achintya
authors.initials: A
authors.lastname: Dhar
authors.forename: Samit Kumar
authors.initials: SK
authors.lastname: Ray
authors.forename: Arup Kumar
authors.initials: AK
authors.lastname: Raychaudhuri