A team from Michigan State University has developed a novel method for "drawing" crystals. This innovative laser crystal drawing technology enables the on-demand generation of crystals at specified times and locations, providing more precise material manufacturing capabilities for fields such as solar cells, LED lighting, and medical imaging. This breakthrough was published in the latest issue of ACS Nano, a journal of the American Chemical Society.
Crystals are ubiquitous, from television screens and smoke detectors to ultrasound devices and sonar systems. Their unique optical and electrical properties underpin modern technological advancements. However, traditional growth methods often result in crystals forming at random times and locations, making it difficult to ensure quality and consistency. This uncertainty has long constrained the manufacturing of high-performance devices.
To address this challenge, the team employed ultrafast laser technology to achieve the first-ever nanoscale "drawing" of crystals. They selected lead halide perovskite crystals for their experiments-materials with significant applications in LEDs, solar cells, and medical imaging.
Unlike previous complex crystal growth steps, the team did not use seed crystals as templates. Instead, they targeted a tiny, shiny gold nanoparticle-less than one-thousandth the diameter of a human hair-with a laser. When a single laser pulse struck the nanoparticle's surface, it generated instantaneous heating, inducing crystal growth through this interaction. Using high-speed microscopy, they could even observe this process in real time.
This laser crystal drawing method resembles laser engraving on metal or wood. It not only enhances the controllability of crystal manufacturing but also provides new research tools for fields like energy, electronics, and quantum technology. Simultaneously, it helps chemists better understand the long-standing mystery of crystal formation.
Using this method, the team can precisely control when and where crystals grow. They can sit at the microscope and witness the very first moment of a crystal's birth, guiding its growth direction. Next, they plan to use lasers of multiple colors to "draw" more complex crystal patterns and attempt to create novel materials unattainable through traditional methods.
