Point defects and electrical compensation in Ultra Wide Band Gap semiconductors
Abstract
The green transition leads to even stronger electrification of the society. Power electronics (PE) play an important role in the collection, delivery and storage of energy, and is a key enabler for energy efficiency, renewable energy and smart grids. PE converters are found in about 40percent of electrified technology for applications ranging from handheld devices through electric vehicles to offshore windmill parks. However, it has been suggested that an increase to approximately 80percent is needed for a sustainable society.Si-based PE components have been optimized to the point where further improvements start to be limited by intrinsic materials properties, notably its bandgap, making both wide and ultra-wide bandgap semiconductors attractive. They can provide components capable of operating at higher voltages, frequencies and temperatures and-or in harsh environments, permitting devices that are that are faster, smaller and more energy efficient than Si-based technology. The wide bandgap SiC and GaN are the most mature candidates, while the ultra-wide band-gap β-Ga2O3 attracts RandD interest thanks to its band-gap of 4.85 eV and high figure-of-merit (see Fig. 1) for the breakdown field (four times higher than for 4H-SiC and GaN). As an example of the interest, the Advanced Propulsion Centre has named β-Ga2O3 – together with diamond, AlN and AlxGa1-xN alloys – the next generation materials for PE and set 2035 as the target for industrial implementation. This is an ambitious, yet necessary target. However, to meet this target and develop ultra-wide band-gap materials for PE at this pace, an imminent knowledge need is to radically increase the understanding of the key property-limiting mechanisms that hinder the development. AlN, AlxGa1-xN alloys, β-Ga2O3 and β-(AlxGa1-x)2O3 alloys all fulfill also the green technology requirement of consisting of earth-abundant elements. The manufacturability is high with mature and scalable technologies, allowing for the optimization of energy efficiency in both material production and device fabrication.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 22, 2024
- Source ID
- FA86552317057
Entities
People
- Filip Tuomisto
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of Helsinki