title: Fabrication of Si/ZnS radial nanowire heterojunction arrays for white light emitting devices on Si substrates.
abstract: Well-separated Si/ZnS radial nanowire heterojunction-based light-emitting devices have been fabricated on large-area substrates by depositing n-ZnS film on p-type nanoporous Si nanowire templates. Vertically oriented porous Si nanowires on p-Si substrates have been grown by metal-assisted chemical etching catalyzed using Au nanoparticles. Isolated Si nanowires with needle-shaped arrays have been made by KOH treatment before ZnS deposition. Electrically driven efficient white light emission from radial heterojunction arrays has been achieved under a low forward bias condition. The observed white light emission is attributed to blue and green emission from the defect-related radiative transition of ZnS and Si/ZnS interface, respectively, while the red arises from the porous surface of the Si nanowire core. The observed white light emission from the Si/ZnS nanowire heterojunction could open up the new possibility to integrate Si-based optical sources on a large scale.
authors.affiliation: Department of Physics, Indian Institute of Technology , Kharagpur, West Bengal 721302, India.
authors.forename: Ajit K
authors.initials: AK
authors.lastname: Katiyar
authors.forename: Arun Kumar
authors.initials: AK
authors.lastname: Sinha
authors.forename: Santanu
authors.initials: S
authors.lastname: Manna
authors.forename: Samit K
authors.initials: SK
authors.lastname: Ray
keywords: Si nanowires; Si/ZnS heterojunction; electroluminescence; metal-assisted chemical etching; nanowire heterojunction; white light emission