Research Reveals 3D Printing of PQD-Polymer at Room Temperature

Abstract

Organic-inorganic perovskite quantum dot (PQD)-polymer composites are emerging optoelectronic materials with exceptional properties that are promising widespread application in next-generation electronics. Advances in the utilization of these materials depend on the development of suitable fabrication techniques to create 3D architectures composed of PQD-polymer for sophisticated optoelectronics. This study introduces a straightforward and effective method for producing 3D architectures of PQD-encapsulated high-performance composites (PQD-HPCs) through direct-ink writing (DIW). This method employs an ink composed of prefabricated PQDs and hydroxypropyl cellulose (HPC) in dichloromethane (DCM). HPC, an appropriate organic-soluble polymer, exhibits optical transparency in the highly volatile DCM and enables the formulation of a stable, room-temperature extrudable ink. The architectures, which are printed by adjusting the halide ratios (Cl, Br, and I) for the compositions of CH3NH3PbBr1.5I1.5, CH3NH3PbBr3, and CH3NH3PbBr1.5Cl1.5, exhibit single peak photoluminescence emissions of red (639 nm), green (515 nm), and blue (467 nm). Optimizing the printing parameters of DIW enables the precise fabrication of programmed and complex PQD-HPC 3D architectures for advanced anti-counterfeiting and information encryption. This method has the potential to enhance the functionality of modern printed electronic devices significantly.

A groundbreaking technology enabling the fabrication of intricate three-dimensional (3D) quantum dot (QD)-based structures at room temperature has been unveiled.

Led by Professor Im Doo Jung from the Department of Mechanical Engineering at UNIST, a recent study has introduced a cutting-edge one-stop perovskite quantum dot (PQD) additive manufacturing technology. This innovative approach eliminates the need for heat treatment, allowing for the creation of complex 3D shapes with exceptional precision, including iconic landmarks like the Eiffel Tower.

Traditionally, shaping QD materials in 3D required prolonged heat exposure, leading to property degradation and shape deformation. However, the newly developed PQD materials exhibit remarkable luminous efficiency and color versatility, offering a game-changing solution for advanced encryption and anti-counterfeiting applications.

By meticulously optimizing key printing variables and utilizing hydroxypropyl cellulose (HPC) polymer and dichloromethane (DCM) as a volatile solvent, the research team achieved stable extrusion of luminescent PQD inks at room temperature. This innovative 3D printing method enables the creation of diverse structures emitting light in red, green, and blue (RGB) colors based on the primary light colors.

The study introduces a sophisticated anti-counterfeiting and encryption system utilizing 3D-printed geometric shapes that leverage the unique light emission properties of PQDs. Demonstrating the potential for enhanced security features in modern printed electronic devices, a 6 x 5 cube architecture array was designed using G- and B-emissive PQD-HPCs for encryption, displaying alphabetic letters (U, N, IS, and T) at 90° intervals.

Lead author Hongryung Jean emphasized the significance of this breakthrough, stating, "Our streamlined QD 3D printing process enables stable manufacturing at room temperature, promising advancements in information encryption systems and optoelectronic printing technologies."

Professor Jung highlighted the impact of this research on expanding QD-based applications and enhancing anti-forgery solutions, stating, "This advancement preserves the photoluminescence properties of PQDs without the need for heat treatments, driving innovation in optoelectronic and energy applications."

The research findings have been published in the March 2024 edition of Advanced Functional Materials, a top-tier academic journal in the field. Supported by the National Research Foundation (NRF) of Korea and other key institutions, this research sets a new standard for encryption technology and anti-counterfeiting measures in the digital age.

Journal Reference

Hongryung Jeon, Muhammad Wajahat, Seobin Park, et al., "3D Printing of Luminescent Perovskite Quantum Dot-Polymer Architectures," Adv. Funct. Mater., (2024).