Recipe for Thin Film-Take 2 Atoms and Microwave for 30 Seconds


Admittedly, it isn’t quite that easy to make thin film and the method using microwave technology is still in its infancy, most recently at the University of Texas, Austin. You may be asking yourself, what is thin film and why do we care if it is made using atoms and microwaves?

The simplest example of thin film in use in your own home today is on the bathroom mirror. A thin film of metal coating is applied to one side which gives it reflectivity. Today, thin film is primarily used in electronic semi-conductors and optical coatings like window tinting.

Ceramic thin film is in wide use today, but it could be used in many more applications. The problem lies in the fact that heat is used to make thin film – very high heat, in fact, which prohibits its use with certain materials such as plastics, for example. This is the problem that researchers at the University of Texas have decided to tackle.

The study at the Crockrell School of Engineering is taking thin film a few steps further.  There are promising developments that could greatly impact the production of thin film batteries and solar cells for use in cell phones and tablets. A very simplistic look at this research is quite interesting in terms of wider applications.

Take a substrate (a solid surface or medium) and use microwave energy to assemble  atoms into a layer of thin film directly onto this material. Microwave energy uses very low heat in this process. Therefore, thin film can be “grown” on heat sensitive surfaces. It is hard to believe that microwaves can convince atoms to assemble themselves into a uniform thin film. This localized heating actually fuses the film to the substrate.

The most significant use of this type of technology would be for solar panels. Thin film solar panels are commercially available now but their cost is quite high. A more cost efficient alternative would greatly expand this market because thin film solar panels are light, durable and easy to install. Currently, inorganic cells are used almost exclusively in the production of these types of panels because they are the better product. Organic films on the market today are too inefficient and have low durability.

The challenge with all thin organic films is to capture as much light as possible using a small amount of material. It is obvious that the need for a product which is comprised of low cost materials, covers less area, absorbs a great deal of light and is durable is worthy of this type of research interest. While it would be helpful to fuel handheld devices like computers and tablets with sun power,  it would be phenomenal to power up a city using material that has the thickness of less than a cellophane wrapper which is also weather resistant and tear proof.

The day might come when we could take a few rolls of cellophane wrapping, microwave them for a few minutes and roll them out on the roof to power our homes. Stranger things have already come to pass.

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