With climate change posing an increasing threat to our environment, scientists believe pressure in thermoelectric generators and thermionic emissions could be the solution.
These alternative energy sources have provided renewable power by recycling “wasted” heat. Examples of this technology are found in gas pipelines and spacecraft. While this has contributed a sizable reduction in the nation’s energy budget, it still hasn’t reached its full potential. The flaw in current thermoelectric compounds is that it only truly succeeds at high heat. Better performance at room temperature is actually the most critical form of renewable energy, but that hasn’t seen improvement in 60 years.
Scientist Liu-Cheng Chen hypothesized that combining pressure and charged chromium particles with lead selenide would produce this greater form of thermoelectric energy. He proved his theory by placing the lead selenide under 30x greater the normal atmospheric pressure. This caused certain changes at the atomic level and produced the most efficient level of room temp thermoelectric generation to date.
Another example of this groundbreaking discovery is thermionic emission of graphene. Thermionic emission happens when a metal is heated and electrons are shot out of the surface. Historically, these emissions have been used to power vacuums and has been experimented with heavily. Emissions from graphene are especially unique because the material is a nanomaterial that’s atomically thin, making it an unusual candidate for this type of energy generation.
Researchers at Singapore University of Technology and Design have created a new general framework to capture thermionic emissions in graphene. Undergrad student, Yueyi Chin, stated that traditional methods of recording this energy can be up to 50% inaccurate! This new theoretical framework helps decrease that inaccuracy by accounting for graphene’s reaction at higher energy states. The electronic properties of graphene are no longer the mystery it used to be. With this new thermionic emission model, we can better see the potential of graphene materials and devices.
Graphene thermionic emissions and pressurized materials will enable scientists to further experiment ways to create renewable energy and reduce our carbon footprint.