Enhanced Thermionic Energy Conversion Using Microplasmas and Diamond Electrodes

Thermionic energy converters are devices that convert heat directly to electricity using a process called thermionic emission. Due to their high operating temperatures (1000°C – 1700°C), thermionic energy converters have the opportunity to be an efficient source of electrical energy. However, the theoretical efficiencies have not been realized due to negative space charge effects and lack of materials with favorable properties. To improve the performance of thermionic energy converters, this work investigates the benefits that microscale plasmas can bring to thermionic energy converters. Microplasmas can be used both in converters, canceling out the effect of negative space charge and enhancing emission current, and outside converters by synthesizing low work function materials such as diamond-containing materials. These methods of enhancement are examined in depth to better understand their underlying physics and to explore new methods to improve the technology of thermionic energy converters.