Journal Article


Jonathan N Coleman
Valeria Nicolosi
John F Donegan
Georg S Duesberg
Lothar Houben
Janina Maultzsch
Nils Scheuschner
Damien Hanlon
Tom Higgins
Paul J King
and 7 others



measurement extinction coefficient size effects confinement quantum confinement two dimensional physical properties exfoliated nanosheets

Edge and confinement effects allow in situ measurement of size and thickness of liquid-exfoliated nanosheets. (2013)

Abstract Two-dimensional nanomaterials such as MoS2 are of great interest both because of their novel physical properties and their applications potential. Liquid exfoliation, an important production method, is limited by our inability to quickly and easily measure nanosheet size, thickness or concentration. Here we demonstrate a method to simultaneously determine mean values of these properties from an optical extinction spectrum measured on a liquid dispersion of MoS2 nanosheets. The concentration measurement is based on the size-independence of the low-wavelength extinction coefficient, while the size and thickness measurements rely on the effect of edges and quantum confinement on the optical spectra. The resultant controllability of concentration, size and thickness facilitates the preparation of dispersions with pre-determined properties such as high monolayer-content, leading to first measurement of A-exciton MoS2 luminescence in liquid suspensions. These techniques are general and can be applied to a range of two-dimensional materials including WS2, MoSe2 and WSe2.
Collections Ireland -> Trinity College Dublin -> PubMed

Full list of authors on original publication

Jonathan N Coleman, Valeria Nicolosi, John F Donegan, Georg S Duesberg, Lothar Houben, Janina Maultzsch, Nils Scheuschner, Damien Hanlon, Tom Higgins, Paul J King and 7 others

Experts in our system

Jonathan Coleman
Trinity College Dublin
Total Publications: 217
Valeria Nicolosi
Trinity College Dublin
Total Publications: 67
John Francis Donegan
Trinity College Dublin
Total Publications: 166
Georg Duesberg
Trinity College Dublin
Total Publications: 116
Damien Hanlon
Trinity College Dublin
Total Publications: 13
Paul J King
Trinity College Dublin
Total Publications: 15