A team at the University of Buffalo has developed a new form of power MOSFET transistor that can handle incredibly high voltages with a minimum thickness, potentially improving the efficiency of electric vehicles’ electrical electronics. Metal oxide semiconductor field effect transistors, also known as MOSFETs, are extremely common components in a variety of consumer electronics, especially in the automotive electronics sector.
Power MOSFET is a switch specifically designed to handle high-power loads. About 50 billion such switches are shipped each year. In fact, they are three-legged, flat electronics that can be used as voltage control switches. When enough (usually quite small) voltage is applied to the gate pin, a connection is established between the other two pins to complete a circuit. They can turn on and off high-power electronics very quickly and are an integral part of electric vehicles.
By creating MOSFET based on zirconium oxide, the team at the University of Buffalo says they have studied how to use thin, paper-like transistors to handle extremely high voltages. When a common epoxy polymer, SU-8, is “passivated”, the zirconium oxide-based transistor can handle more than 8,000 volts of voltage in laboratory tests before it fails, a figure that researchers say is significantly higher than similar transistors made with silicon carbide or nitride.
In the experiment, the band gap number of zirconium oxide was 4.8 electron volts, which is impressive. Band gap is a measure of the energy required for an electron to enter a conductive state, and the wider the band gap, the better the effect. Silicon is the most common material in electrical electronics, with a band gap of 1.1 electron volts. The band gaps of silicon carbide and niobium nitride are 3.4 and 3.3 electron volts, respectively. As a result, the 4.8 electron volt band gap of zirconia gives it a leading position.
By developing a MOSFET that can handle very high voltages at very small thicknesses, the Buffalo team hopes that its work will contribute to smaller, more efficient power electronics such as electric vehicles, locomotives, aircraft, microgrid technology, and potential solid-state transformers.