Power electronics with wide bandgap materials: Toward greener, more efficient technologies

Abstract

IntroductionPower electronics is the branch of electronics specifi cally dealing with collecting, delivering, and storing energy, including general and local/commodity energy supplies, by conversion and control of electrical power.1 Specifi c applications range from power supply systems to motor vehicle drives, 2 photovoltaic and fuel cell converters, inverters, and high-frequency heating, 3 among many others. The impact of power electronics has already been signifi cant and is anticipated to be even more so in the future for effi cient energy production and management.As in most other electronics areas, silicon also has been the predominant semiconductor in power electronics to date. However, with wide bandgap materials power electronic components are faster, smaller, more effi cient, and more reliable than their Si-based counterparts. Moreover, they permit the operation of devices at higher voltages, temperatures, and frequencies, 4 making it possible to reduce volume and weight in a wide range of applications. This could lead to large energy savings in industrial and consumer appliances, accelerate widespread use of electric vehicles and fuel cells, and integrate renewable energy into the electric grid.The power electronics market as a whole was about $20 billion in 2012, and power electronics will remain one of the most attractive branches of the semiconductor industry over the next decade. 5 The latest power electronics market forecasts 6 predict an increase of 60% for low-voltage technologies (below 900 V) by the year 2020, accompanied by an approximately 100% market increase for medium (1.2-1.7 kV) and high voltage (2 kV and above) technologies. This implies that the largest market increase in this sector over the next decade (medium and high voltage) will rely on semiconductor technologies beyond silicon (also see article by Okumura in this issue). This can be likened to a second revolution, equivalent to the introduction of large scale fabrication of silicon complementary metal oxide semiconductor (CMOS) technology, which led to the commoditization of electronics and formed the basis of our modern technological era. The power electronics revolution could be setting the basis for a world centered on greener technologies: improved energy conversion effi ciencies, faster switching, and more compact, lighter systems with better thermal management and tolerance will have tremendous impact on industrialization and energy systems, encompassing energy savings, renewable energy systems, and Greener technologies for more effi cient power generation, distribution, and delivery in sectors ranging from transportation and generic energy supply to telecommunications are quickly expanding in response to the challenge of climate change. Power electronics is at the center of this fast development. As the effi ciency and resiliency requirements for such technologies can no longer be met by silicon, the research, development, and industrial implementation of wide bandgap semiconductors such as gallium nitride (GaN) and sil...

Terahertz cyclotron resonance spectroscopy of an AlGaN/GaN heterostructure using a high-field pulsed magnet and an asynchronous optical sampling technique

“…High electron mobility transistors (HEMTs) based on the GaN materials system are of great interest for applications in the field of power electronics due to their combination of high electric breakdown field and high electron mobility. 1 The characterization of the two-dimensional electron gas (2DEG) formed at the GaN/AlGaN interface in HEMT structures, caused by the large differences in piezoelectric and spontaneous polarizations, has already revealed an advantageous high electron mobility and large sheet carrier concentration in the GaN channel. 2 To optimize the performance of such structures requires knowledge of the electron effective mass within the 2DEG, a fundamental parameter in determining electronic transport.…”

Formation and Removal of Carbon Film on Silicon Carbide Surface Using Chlorine Trifluoride Gas

“…Semiconductor silicon carbide (SiC) materials are produced and used for developing power devices 1 in order to significantly reduce the electric power loss. To industrially produce the silicon carbide wafers, a quick mechanical and chemical surface process should be developed.…”

X‐Ray Diffraction Microstrain Analysis for Extraction of Threading Dislocation Density of GaN Films Grown on Silicon, Sapphire, and SiC Substrates

“…GaN(0001)‐on‐Si(111) (gallium‐nitride‐on‐silicon) wide bandgap semiconductor technology is pushing the limits of high‐power semiconductors by making systems more energy efficient . Notwithstanding their qualities, GaN on silicon substrates is highly defective and stressed, with high densities of threading dislocations (TDs) observed in these materials, usually in the range of 10 8 –10 10 cm −2 .…”

“…GaN(0001)-on-Si(111) (gallium-nitride-on-silicon) wide bandgap semiconductor technology is pushing the limits of high-power semiconductors by making systems more energy efficient. [1] Notwithstanding their qualities, GaN on silicon substrates is highly defective and stressed, with high densities of threading dislocations (TDs) observed in these materials, usually in the range of 10 8 -10 10 cm À2 . Different concentrations of TD have been shown to affect the performance of GaN-on-Si-based devices, especially their dynamic behavior, [2,3] and the study of their density is therefore essential to understand the device performance.…”