Photo-patternable QD/siloxane composite with high thermal stability for color filters

Abstract

Incorporation of quantum dots (QDs) into color filters (CFs) are desired for less energy loss and wider viewing angle compared to a conventional display. However, aggregation and vulnerability to heat, moisture, and chemicals in the photo-patternable matrix are critical issues of the QD-CFs with high QDs concentration. Herein, we fabricated red (10 wt %) and green (20 wt %) QD-CFs using photolithography of QD/siloxane ink containing secondary thiol monomer. Ligand-exchanged QDs were chemically incorporated in methacrylate oligosiloxane resin. QD/siloxane composite showed superior stability under harsh heat and moisture (85 °C/5% RH and 85 °C/85% RH) conditions and chemicals (EtOH, HCl, and NaOH) compared to conventional QD/PR (commercial negative photoresist). QD-CFs (10 μm thick) effectively converted blue light emitted from LED chip into red and green light, and the obtained white PL through QD-CF showed wide color gamut, which was 108% relative to NTSC. From these advantages, QD/siloxane composite will be beneficial as color-conversion photoresists are to be used as color filters in liquid crystal displays, micro light-emitting diodes, and organic light-emitting diodes.