Solution Synthesis and Optical Properties of Transition-Metal-Doped Silicon Nanocrystals

Benjamin F P McVey; Justinas Butkus; Jonathan E Halpert; Justin M Hodgkiss; Richard D Tilley

doi:10.1021/acs.jpclett.5b00589

Solution Synthesis and Optical Properties of Transition-Metal-Doped Silicon Nanocrystals

J Phys Chem Lett. 2015 May 7;6(9):1573-6. doi: 10.1021/acs.jpclett.5b00589. Epub 2015 Apr 14.

Authors

Benjamin F P McVey^{1

2}, Justinas Butkus¹, Jonathan E Halpert¹, Justin M Hodgkiss¹, Richard D Tilley^{1

2}

Affiliations

¹ †School of Chemical and Physical Sciences and the MacDiarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington, Wellington 6012, New Zealand.
² ‡School of Chemistry and Electron Microscopy Unit of the Mark Wainwright Analytical Centre, University of New South Wales Sydney, Chemical Sciences Building Kensington, Sydney, New South Wales 2052, Australia.

PMID: 26263316
DOI: 10.1021/acs.jpclett.5b00589

Abstract

A new synthetic method was developed to produce a range of transition-metal (Mn, Ni, and Cu) doped silicon nanocrystals (Si NCs). The synthesis produces monodisperse undoped and doped Si NCs with comparable average sizes as shown by transmission electron microscopy (TEM). Dopant composition was confirmed by EDX (energy dispersive X-ray spectroscopy). The optical properties of undoped and doped were compared and contrasted using absorption (steady-state and transient) and photoluminescence spectroscopy. Doped Si NCs demonstrated unique dopant-dependent optical properties compared to undoped Si NCs such as enhanced subgap absorption, and 40 nm shifts in the emission. Transient absorption (TA) measurements showed that photoexcitations in doped Si NCs relaxed via dopant states not present in undoped Si NCs.

Keywords: nanocrystal; optical properties; quantum dot; silicon; solution synthesis.