On the in Situ 3D Electrostatic Directed Assembly of CdSe/CdZnS Colloidal Quantum Nanoplatelets Towards Display Applications.

Hypothesis: Due to their unique quantum yield and photostability performances, quantum nanoplatelets are very promising building blocks for future generations of displays. The directed assembly of such col-loidal nano-objects in the shape of micro-pixels is thus the next mandatory step to reach this goal. Selectively trapping them on electrostatically charged patterns by nanoxerography could be a versatile and appealing strategy but requires a full understanding of the assembly mechanisms in order to make the most of their integration.Experiments: We propose an experimental platform based on a smart resealable microfluidic chip cou-pled to an inverted optical fluorescence microscope and a high-speed camera for in situ access of such assembly mechanisms, using CdSe/CdZnS quantum nanoplatelets as model nano-objects. The photoluminescence signal of the nanoplatelet patterns is thus recorded in real time during their assembly and data extracted after image processing.Findings: The coupling of experimental results and numerical simulations evidences the main role of advection at the origin of this directed nanoparticle trapping. Deep understanding of the involved mech-anisms and tuning of experimental parameters allow to make high resolution quantum nanoplatelet based micro-pixels with a fine control of their lateral and vertical dimensions.(c) 2022 Elsevier Inc. All rights reserved.