The Influence of Light Exposure on Electrohydrodynamic (EHD) Printing of CdS/CdSe Quantum Dots

Abstract

Electrohydrodynamic (EHD) printing is a high-resolution deposition technique widely used for patterning functional nanomaterials. The printability of inks in EHD printing is highly dependent on factors such as polarizability, dielectric constant, and surface tension, which determine the formation and stability of the Taylor cone. While EHD printing is typically controlled through electric field modulation, external stimuli such as light exposure could provide an additional tuning parameter, yet its influence remains largely unexplored.This study investigates whether 395 nm light enhances the EHD printability of CdSe/CdS quantum dots (QDs) by affecting the material's response under a fixed voltage. Experimental results show that, under identical voltage conditions, printing is significantly enhanced with 395 nm illumination, whereas minimal deposition occurs in the absence of light. This finding suggests that optical excitation may influence charge dynamics or dipole formation within the ink, potentially altering its response to the applied electric field. By demonstrating a clear correlation between light exposure and enhanced EHD printing, this work provides a foundation for further exploration of optically controlled material deposition. Understanding this effect could lead to new strategies for precision printing of optoelectronic materials, enabling tunable and high-resolution patterning techniques.