Inkjet-Printed Imbedded Graphene Nanoplatelet/Zinc Oxide Bulk Heterojunctions Nanocomposite Films for Ultraviolet Photodetection.

A ZnO sol-gel precursor (ZnOPr) and graphene nanoplatelets (GnPs) are mixed into a composite ink for inkjet printing photodetectors with bulk heterojunctions of ZnO/GnP on a heated SiO/Si substrate. Heating of the SiO/Si wafers at ∼50 °C was found optimal to prevent segregated droplets on the hydrophobic surface of the SiO/Si substrate during printing. After printing the ZnO/GnP channels, thermal annealing at 350 °C for 2 h was performed for crystallization of ZnO and formation of the ZnO/GnP heterojunctions.