Molten Salt–Assisted Screen Printing of Highly Textured Zn2SiO4 Films with Enhanced Deep UV Emission

Abstract

A novel and scalable approach for the fabrication of deep ultraviolet (UV) emitting materials is presented through the synthesis of highly textured zinc silicate films using screen printing assisted by a NaCl-KCl eutectic flux. This work provides the first demonstration of intrinsic deep UV emission in screen-printed Zn2SiO4 films and establishes a correlation between processing conditions, interfacial phase evolution, and optical response. The films exhibited strong preferential orientation along the (300) plane with Lotgering factors reaching up to 0.94. Interface analysis reveals the pivotal role of flux-mediated phase transformations in governing film growth dynamics and surface morphology. Detailed luminescence studies identified intense deep UV emission at 4.43 eV (280 nm), attributed to intrinsic electronic transitions within the Zn2SiO4 material. Synchrotron radiation studies indicate that the emission involves band-to-band transitions and excitonic processes influenced by the local structural environment. Notably, emission intensity correlates strongly with both crystallographic texturing and the quality of the film-substrate interface, highlighting the key role of interface and structural control in enhancing deep UV emission. The demonstrated method offers a promising pathway for the development of mercury-free and rare-earth-free deep UV emitters for next-generation photonic and optoelectronic applications.