Approaching Bulk Mobility in PbSe Colloidal Quantum dots 3D Superlattices.

Three-dimensional superlattices made of colloidal quantum dots are a promising candidate for the next generation of optoelectronic devices as they are expected to exhibit a unique combination of tunable optical properties and coherent electrical transport through minibands. While most of the previous work was performed on two-dimensional arrays, the control over the formation of these systems has been lacking, where limited long-range order and energetical disorder have so far hindered the potential of these metamaterials, giving rise to disappointing transport properties. Here we report that nanoscale-level controlled ordering of colloidal quantum dots in three dimensions and over large areas allows achieving outstanding transport properties. The measured electron mobilities are the highest ever reported for a self-assembled solid of fully quantum-confined objects. This ultimately demonstrates that optoelectronic metamaterials with highly tunable optical properties (in this case in the short-wavelength infrared spectral range) and charge mobilities approaching the one of bulk semiconductor can be obtained. This finding paves the way towards a new generation of optoelectronic devices. This article is protected by copyright. All rights reserved.