Size tuning at full yield in the synthesis of colloidal semiconductor nanocrystals, reaction simulations and experimental verification

We review recent work on the use of reaction simulations that implement precursor conversion and nanocrystal nucleation and growth to identify strategies for tuning the size of colloidal nanocrystals at close to full yield in the hot injection synthesis. The concepts the simulations are based on - including the central role of the rate of precursor conversion - are introduced, a characteristic model synthesis is discussed and qualitative agreement with experimental results is demonstrated using a synthesis of zincblende CdSe nanocrystals. Based on these results, the possibility of size tuning at close to full yield is discussed and useful strategies for implementation are explored through simulations and verified using the same zincblende CdSe synthesis. These strategies involve varying the precursor conversion rate and the solubility of the solute formed by the precursor conversion. Next, it is shown how these various concepts can be applied to control the final nanocrystal size and the composition of homogeneous alloys in a recently developed phosphine-free synthesis of CdSe and CdSe1-xSx nanocrystals. Finally, an outlook is given for future research on the simulation and experimental verification of colloidal synthesis by hot injection. (C) 2013 Elsevier B.V. All rights reserved.