Surface processing for area selective mist deposition of nanocrystalline quantum dot films

This study explores surface engineering for the purpose of selective deposition of cadmium selenide (CdSe) nanocrystalline quantum dot (NQD) thin films using the process of mist deposition. Surfaces of silicon and/or glass substrates were made uniformly hydrophobic by exposure to trichloro (1H,1H,2H,2H-perfluorooctyl) silane (FOTS) anhydrous hexane solution. Subsequent localized UV exposure increased surface energy making it locally hydrophilic, and thus, allowing area selective deposition of NQD film. Electric field involved in the mist deposition process was shown to reverse process selectivity through the electrowetting effect. The role of IR rapid optical surface treatment (ROST) in controlling surface energy of FOTS material was explored. Findings of this study will allow area selective deposition of the variety of NQD precursors in the form of colloidal solution.