3D Printing of Metal Halide Perovskite Whispering-Gallery-Mode Microring Lasers

Metal halide perovskite nanocrystals, or quantum dots, due to their size-dependent, narrow-band photoluminescence (PL) characteristics originating from the quantum confinement effect [1], hold significant potential as gain materials for various technologies [2]. Their solution processability and size-tunable optical transitions make them versatile across the visible and infrared spectrum [3] by controlling the size, and they have been considered promising materials for optoelectronic applications. However, a lack of techniques for high-precision and high-resolution deposition and patterning of perovskite quantum dots on a selected area of a substrate limits the realization of such devices [1]. In the field of semiconductor lasers, there is a growing demand for low-threshold and narrow linewidth lasers. Perovskite whispering gallery mode (WGM) micro-resonators, known for their low optical losses and miniature sizes, have emerged as excellent candidates for meeting these requirements to establish high-performance lasing [4]. However, the current fabrication technique of perovskite WGM resonator highly relies on electron beam lithography, photolithography, nanoimprinting, etc. which are energy- and labour-intensive, in stark contrast with the industrial low-cost requirements [5].<br/><br/>Here, we report on the utilization of electrohydrodynamic (EHD) 3D printing to produce WGM laser resonators with the assembly of CsPbBr₃ quantum dots. We demonstrate that EHD 3D printing provides a flexible and scalable manufacturing method for fabricating microring laser resonators with high-precision and programmed lasing characteristics. Unlike traditional lithography techniques, EHD printing allows for the direct deposition of perovskite quantum dots in a layer-by-layer fashion, enabling the creation of intricate 3D laser cavities with submicron and nanoscale features. By leveraging the benefits of EHD printing, such as flexibility, scalability, and cost-effectiveness, this approach eliminates the need for expensive lithography equipment and complex processes [6], making it a promising technique for high-performance optical device development, particularly in laser technology. Overall, our research contributes to advancing additive manufacturing technologies in the fabrication of micro light sources and expanding the applications of perovskite quantum dots in laser technology.<br/><br/>[1] J.-S. Park <i>et al.</i>, “Alternative Patterning Process for Realization of Large-Area, Full-Color, Active Quantum Dot Display,” <i>Nano Lett.</i>, vol. 16, no. 11, pp. 6946–6953, Nov. 2016, doi: 10.1021/acs.nanolett.6b03007.<br/>[2] V. I. Klimov <i>et al.</i>, “Single-exciton optical gain in semiconductor nanocrystals,” <i>Nature</i>, vol. 447, no. 7143, Art. no. 7143, May 2007, doi: 10.1038/nature05839.<br/>[3] B. le Feber, F. Prins, E. De Leo, F. T. Rabouw, and D. J. Norris, “Colloidal-Quantum-Dot Ring Lasers with Active Color Control,” <i>Nano Lett.</i>, vol. 18, no. 2, pp. 1028–1034, Feb. 2018, doi: 10.1021/acs.nanolett.7b04495.<br/>[4] V. I. Klimov <i>et al.</i>, “Optical Gain and Stimulated Emission in Nanocrystal Quantum Dots,” <i>Science</i>, vol. 290, no. 5490, pp. 314–317, Oct. 2000, doi: 10.1126/science.290.5490.314.<br/>[5] Y. Liu, F. Li, and W. Huang, “Perovskite micro-/nanoarchitecture for photonic applications,” <i>Matter</i>, vol. 6, no. 10, pp. 3165–3219, Oct. 2023, doi: 10.1016/j.matt.2023.05.043.<br/>[6] V. Harinarayana and Y. C. Shin, “Two-photon lithography for three-dimensional fabrication in micro/nanoscale regime: A comprehensive review,” <i>Opt. Laser Technol.</i>, vol. 142, p. 107180, Oct. 2021, doi: 10.1016/j.optlastec.2021.107180.