GaN changes the game in power conversion
- PDF / 873,710 Bytes
- 3 Pages / 585 x 783 pts Page_size
- 20 Downloads / 165 Views
GaN changes the game in power conversion The pitch The form of electrical energy that is required depends strongly on the function to be performed. For example, a laptop computer typically needs 18 V direct current (dc). The conversion from the 110 V alternating current (ac) outlet to the 18 V dc is performed by a voltage converter. The dc power from a photovoltaic panel needs to be converted to ac to feed into the grid by a circuit called an inverter. Such a dc-to-ac power conversion also occurs in hybrid cars where dc energy from the battery is converted to ac energy to drive the electric motors. Consequently power conversion is ubiquitous with an annual market value of over $7 billion growing at a compound annual growth rate of over 12.6%. The devices being used for power
TECHNOLOGY ADVANCES seeks materials developments on the threshold of commercialization. Send suggestions to MRS Bulletin at [email protected].
conversion are Si-based diodes and transistors, predominantly metal oxide semiconductor field-effect transistors and insulated gate bipolar transistors. While Si has performed well in the past, it has reached its material limits for power conversion. Thus increases in efficiency are becoming more difficult to achieve. Inefficient electric power conversion results in hundreds of terawatts of lost energy across the electrical grid in the United States, equivalent to 318 coal-fired power plants. The cost to the U.S. economy is $40 billion annually, which represents over 10% of all the power generated in the United States today. The losses in electrical power conversion are larger than all the electricity produced from the alternative energy sources of power combined by over an
MRS BULLETIN
order of magnitude. To eliminate these losses requires moving to a new materials system to produce an ideal switch, that is, the ability to hold large voltages when off and dissipate negligible loss when passing current in the on state. According to the company Transphorm, the optimum and most economical materials to perform this function are based on gallium nitride. Transphorm’s GaN-based power solutions increase efficiency, reduce system size, and simplify overall product design and can eliminate up to 90% of all electric conversion losses from heating, ventilation, and air-conditioning systems (HVAC) and solar panels.
The technology The power-conversion devices that are
•
VOLUME 36 • NOVEMBER 2011
•
www.mrs.org/bulletin
853
NEWS & ANALYSIS TECHNOLOGY ADVANCES
The AlGaN/GaN heterostructure used to fabricate Transphorm’s diodes and transistors. The highelectron-mobility channel is also shown.
integrated into the final module solutions are based on the aluminum gallium nitride (AlGaN)/gallium nitride (GaN) heterostructure fabricated into both diodes and transistors. The transistor is a high-electron-mobility transistor. The cross section of the material structure and the device design of a typical device is shown in the figure. The current is carried by a two-dimensional electron gas
possessing high electro
Data Loading...
