Electric cars are popular, and people love them, but they don’t like the bulky batteries that come with it, nor do they like the related power systems that take up cargo space. A team from the University at Buffalo is looking to change that by developing a gallium oxide-based transistor.
The new form of power, MOSFET, can take on incredibly high voltages with minimal thickness, prefiguring an efficiency boost in the power electronics of electric vehicles. MOSFETs, or Metal-oxide semiconductor field-effect transistors, are one of the most common components found in all kinds of consumer electronics, and particularly in automotive electronics. Power MOSFETs are specifically designed to handle significant power loads, and about 50 billion are manufactured and shipped each year.
MOSFETs are an electronic component that acts as voltage-controlled switches. They look like flat squares with three pins sticking out, and when a voltage is applied to the gate pin, it forms a connection between the other two pins, completing a full circuit. The transistor can rapidly switch high-power electronics on and off, and they’re a fundamental part of electric vehicles.
The team claims that by creating MOSFETs based on gallium oxide, they’ve figured out how to make it handle extremely high voltages using paper-thin transistors. When the researchers tested out the transistor in the lab, they “passivated” it with a layer of an epoxy-based polymer known as SU-8. The gallium oxide-based transistor was able to handle more than 8,000 volts before it broke down.
The most impressive part of all is the gallium oxide’s bandgap figure of 4.8 electron volts. What does the bandgap do? It measures how much energy is required to jolt an electron into a conducting state, which means the wider the bandgap, the better. The most widely used material in power electronics is silicon, which has a 1.1 electron volt bandgap, while gallium nitride and silicon carbide have 3.4 and 3.3 electron volt bandgaps. Therefore, gallium oxide’s 4.8 electron volt bandgap is remarkable.
The Buffalo team hopes that by developing a MOSFET that can handle considerably high voltages at a small thickness, it could contribute to smaller, more efficient power electronics for EVs, micro-grid technologies, aircraft, and solid-state transformers.
Uttam Singisetti, the study‘s lead author, said:
To really push these technologies into the future, we need next-generation electronic components that can handle greater power loads without increasing the size of power electronics systems.
Eventually, these high-efficiency systems could provide electric vehicles with more range. However, in the meantime, further experimentation is needed to test the field strength of these new and improved transistors.
