Aspiration-assisted fabrication of patterned quantum dot films for photo-emissive color conversion

The fabrication of patterned quantum dot (QD) films is of great importance for color displays based on photo-emissive color conversion. In this work, a novel and precise alignment-free fabrication method of patterned quantum dot color conversion (QDCC) films was proposed by introducing into aspiration-assisted lithography. QDs dispersed in mixed polymer/toluene solvent can be imbibed via predetermined micro-channels with the assist of aspiration. The results show that uniform QDCC films with multicolor QDs could be achieved by adjusting the polymer/toluene ratios and the aspiration time. Superfine QD patterns with a width of around 8 mu m could also be obtained by varying the interfacial free energies of substrates. A color conversion device using a turquoise OLED and the QDCC films incorporated with distributed Bragg reflector have been demonstrated, exhibiting a conversion efficiency up to 23.27%.

Automated summary

A novel and precise alignment-free method for fabricating patterned quantum dot color conversion films has been proposed in this work, achieving uniform multicolor QDs and superfine QD patterns by adjusting material ratios and aspiration time. The color conversion device using a turquoise OLED and QDCC films incorporated with distributed Bragg reflector has shown a conversion efficiency up to 23.27%.