The use of dithio- and diselenocarbamates as precursors to nanoscale materials

The effectiveness of dithio- and diselenocarbamates of several metals as pr ecursors for a range of nanoscale semiconducting materials has been demonst rated. Tailoring the precursor alkyl groups, can lead to: self-capping quan tum dots, size selection (growth time and temperature) and clean decomposit ion. Here we report the different outcomes achieved when using the dithio- and diselenocarbamates, [E(2)CNMe(n)Hex] analogue as opposed to the [E(2)CN Me(n)Octadecyl] compounds. Growth studies using [Cd(Se(2)CNMe(n)Hex)(2)] showed that there is initiall y linear growth in the average diameter of the nanoparticles in trioctylpho sphine oxide (TOPO at 250 degreesC). However, for precursor such as [Bi(S(2 )CNMe(n)Octadecyl)(3)], a radically different approach can be taken. These long chain dithiocarbamates can be used to synthesise self-capped quantum d ots, via a simple thermolysis reaction. (C) 2001 Elsevier Science B.V. All rights reserved.