M J Fernée et al 2004 Nanotechnology 15 16 doi:10.1088/0957-4484/15/1/003
M J Fernée, J Warner, A Watt, S Cooper, N R Heckenberg and H Rubinsztein-Dunlop
Show affiliationsEffective surface passivation of lead sulfide (PbS) nanocrystals (NCs) in an aqueous colloidal solution has been achieved following treatment with CdS precursors. The resultant photoluminescent emission displays two distinct components, one originating from the absorption band edge and the other from above the absorption band edge. We show that both of these components are strongly polarized but display distinctly different behaviours. The polarization arising from the band edge shows little dependence on the excitation energy while the polarization of the above-band-edge component is strongly dependent on the excitation energy. In addition, time-resolved polarization spectroscopy reveals that the above-band-edge polarization is restricted to the first couple of nanoseconds, while the band edge polarization is nearly constant over hundreds of nanoseconds. We recognize an incompatibility between the two different polarization behaviours, which enables us to identify two distinct types of surface-passivated PbS NC.
81.07.Bc Nanocrystalline materials
Condensed matter: electrical, magnetic and optical
Issue 1 (January 2004)
Received 14 May 2003, in final form 9 July 2003
Published 10 November 2003
M J Fernée et al 2004 Nanotechnology 15 16
L M Kettle et al 2004 J. Phys.: Condens. Matter 16 1011
P H Thomas 1952 Br. J. Appl. Phys. 3 385
A M Akulshin et al 2003 J. Opt. B: Quantum Semiclass. Opt. 5 S479
Paul M Alsing et al 2004 J. Opt. B: Quantum Semiclass. Opt. 6 S834
D Boley and G H Golub 1987 Inverse Problems 3 595
A A Clerk et al 2008 New J. Phys. 10 095010
John Clarke et al 2002 Phys. Scr. 2002 173
David A W Barton et al 2007 Nonlinearity 20 809
Pengpeng Zhang et al 2006 New J. Phys. 8 200