Controlling anisotropy is a key concept to generate complex functionality in advanced materials. For this, oriented attachment of nanocrystal building blocks, a self assembly of particles into larger single crystalline objects, is one of the most promising approaches in nanotechnology. We report here the 2D oriented attachment of PbS nanocrystals into ultra-thin single crystal sheets with dimensions on the micrometer scale. We found that this process is initiated by co-solvents which alter nucleation and growth rates during the primary nanocrystal formation and finally driven by dense packing of oleic acid ligands on {100} facets of PbS. The obtained nanosheets can be readily integrated in a photo-detector device without further treatment.
@article{arxiv.1103.2920,
title = {Ultra-thin PbS sheets by two-dimensional oriented attachment},
author = {Constanze Schliehe and Beatriz H. Juarez and Marie Pelletier and Sebastian Jander and Denis Greshnykh and Mona Nagel and Andreas Meyer and Stephan Foerster and Andreas Kornowski and Christian Klinke and Horst Weller},
journal= {arXiv preprint arXiv:1103.2920},
year = {2015}
}