Tilted Face-Centered-Cubic Supercrystals of PbS Nanocubes

We demonstrate a direct fabrication of PbS nanocube supercrystals without size-selection pretreatment on the building blocks. Electron microscopic and synchrotron small angle X-ray scattering analyses confirm that nanocubes pack through a tilted face-centered-cubic (fcc) arrangement, that is, face-to-face along the < 110 >(super) direction, resulting in a real packing efficiency of as high as similar to 83%. This new type of superstructure consisting of nanocubes as building blocks, reported here for the first time, is considered the most stable surfactant-capped nanocube superstructure determined by far.