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Polarised Photoluminescence from Surface-Passivated PbS Nanocrystals

M. J. Fernee·J. Warner·A. Watt·S. Cooper·N. R. Heckenberg·H. Rubinsztein-Dunlop
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Abstract

Effective surface-passivation of PbS nanocrystals in 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 polarised but display distinctly different behaviours. The polarisation arising from the band-edge shows little dependence on the excitation energy while the polarisation of the above-band-edge component is strongly dependent on the excitation energy. In addition, time resolved polarisation spectroscopy reveals that the above-band-edge polarisation is restricted to the first couple of nanoseconds, while the band-edge polarisation is nearly constant over hundreds of nanoseconds. We recognise an incompatibility between the two different polarisation behaviours, which enables us to identify two distinct types of surface-passivated PbS nanocrystal.

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M. J. Fernee, J. Warner, A. Watt, S. Cooper, N. R. Heckenberg, H. Rubinsztein-Dunlop. 2003-06-12. Polarised Photoluminescence from Surface-Passivated PbS Nanocrystals. https://doi.org/10.1088/0957-4484%2F15%2F1%2F003

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