title: Synthesis of tetrahedral quasi-type-II CdSe-CdS core-shell quantum dots.
abstract: Synthesis of colloidal nanocrystals of II-VI semiconductor materials has been refined in recent decades and their size dependent optoelectronic properties have been well established. Here we report a facile synthesis of CdSe-CdS core-shell heterostructures using a two-step hot injection process. Red-shifts in absorption and photoluminescence spectra show that the obtained quantum dots have quasi-type-II alignment of energy levels. The obtained nanocrystals have a heterostructure with a large and highly faceted tetrahedral CdS shell grown epitaxially over a spherical CdSe core. The obtained morphology as well as high resolution electron microscopy confirms that the tetrahedral shell have a zinc blende crystal structure. A phenomenological mechanism for the growth and morphology of the nanocrystals is discussed.
authors.affiliation: Division of Functional Materials, Royal Institute of Technology (KTH), Stockholm, 16440, Sweden.
authors.forename: Abhilash
authors.initials: A
authors.lastname: Sugunan
authors.forename: Yichen
authors.initials: Y
authors.lastname: Zhao
authors.forename: Somak
authors.initials: S
authors.lastname: Mitra
authors.forename: Lin
authors.initials: L
authors.lastname: Dong
authors.forename: Shanghua
authors.initials: S
authors.lastname: Li
authors.forename: Sergei
authors.initials: S
authors.lastname: Popov
authors.forename: Saulius
authors.initials: S
authors.lastname: Marcinkevicius
authors.forename: Muhammet S
authors.initials: MS
authors.lastname: Toprak
authors.forename: Mamoun
authors.initials: M
authors.lastname: Muhammed