Electrified atomic vapor system enables new nanomaterial mixtures

Vapor-phase synthesis, a technique used to create very pure and scalable nanomaterials and coatings, has great promise for the electronic, optical, aerospace, energy and environment, and semiconductor industries.

Now, using a form of electrified vapor under atmospheric pressure, a team led by Yale’s Liangbing Hu has developed a system that’s more versatile, quicker and cheaper. The results are published in Nature Synthesis. The project is a collaboration with Prof. Yiguang Ju of Princeton University and Princeton Plasma Physics Laboratory. The study’s lead author, Xizheng Wang, a former postdoctoral researcher in Hu’s lab, is a professor at University of California Irvine.

Vapor-phase synthesis converts materials by vaporizing and then returning them to solid form, either as particles or as thin coatings. The challenge, though, is that doing so in atmospheric conditions and being able to control the properties of the final product is tricky. That’s partly because some materials have particularly high boiling points, which require the addition of complex, high-power systems, such as electron beams, plasma, and pulsed lasers.

These systems are costly to purchase and maintain. Further, to achieve optimal results, many conventional methods require vacuum pressure, which is also expensive and difficult to maintain.

The Hu lab, though, has solved this through a new method they call electrified vapor deposition (EVD). Essentially, it uses an electrified carbon paper heater to quickly reach extremely high temperatures, which instantly vaporizes and dissociates the material and creates atomic vapor.

When this atomic vapor mixes with the surrounding argon gas (kept at room temperature), it rapidly cools and nucleates in a way that’s highly uniform. This results in pure nanomaterial products and thin films with excellent compositional and structural control. Critical to this method is that the system is specifically designed for continuous flow and rapid cooling of the vapor.

The EVD system allows for the mixing of a wide range of materials that typically can’t be created using conventional means. It’s quick, low-cost, and can be used in atmospheric conditions without requiring vacuum systems and other expensive equipment.