Micron‐Scale Patterning of High Quantum Yield Quantum Dot LEDs

Micron‐scale resolution patterning of colloidal quantum dots (QDs) is demonstrated by adopting inkjet printing as a technique that is solvent and room temperature compatible, maintains optical and electronic properties of printed QD films, and results in minimal materials waste during the deposition process. With a combination of solvent engineering and substrate patterning single prints of PbS–CdS core–shell QDs (with peak photoluminescence emission at λ = 1270 nm wavelength) are deployed to form QD films of nanoscale‐thickness, with regular micron‐scale patterns. Inkjet printing of infrared QD films is chosen as a case study for manufacture of QD‐light emitting diodes (QD‐LEDs), and demonstrates devices with a record peak external quantum efficiency in excess of 2% that is finally comparable with state‐of‐the‐art spin‐coated prototypes.