Micro- and Nanoscale Patterning of Fluorescent Materials via Coaxial Electrohydrodynamic Jet Printing

The nano-patterned processing of fluorescent materials is an essential technology for the fabrication of optoelectronic devices. However, traditional methods such as photolithography and inkjet printing suffer from low resolution, poor material compatibility and process damage. In this study, a novel coaxial electrohydrodynamic jet printing technique is proposed to achieve controlled deposition with micro- and nanoscale precision by constraining the fluorescent ink jet through a sheath layer of high-viscosity silicone oil. The method utilizes the viscous shear effect of the outer layer of silicone oil to suppress jet instability and substrate wetting, resulting in a minimum feature linewidth of 190 nm. Experiments have demonstrated the applicability of this method to a wide range of fluorescent materials such as inorganic quantum dots (CdSe/ZnS) and organic polymers (F8-BT). Large-area nanowire arrays were efficiently fabricated on silicon substrates, and diverse structures including straight lines, curves, and lattices were obtained, establishing a versatile platform for micro- and nanoscale fluorescent patterning.