(YIP) EFFECT OF EXTREME ELECTRIC FIELDS ON THERMAL TRANSPORT IN WIDE-GAP SEMICONDUCTORS
Abstract
Wide bandgap semiconductors, such as GaN, Ga2O3, SiC, hold great promise for nextgeneration power electronic applications. A main limitation, however, is the requirement of efficient heat dissipation from these high-power devices. In particular, the active regions in power electronic devices with the highest temperature during operation are the same areas that withstand the highest electric field, up to extremely levels as high as 5 MV-cm. Therefore, how the extremely electric field impacts the thermal transport properties of these materials is of crucial importance for efficient thermal management and electro-thermal codesign of future devices. Surprisingly, little previous studies have focused on this important issue and it remains unclear which factors are the major contributors to the field-dependent thermal transport in wide-gap semiconductors. The overarching goal of the proposed research is to bridge this fundamental knowledge gap in materials science with a combined theoretical and experimental approach. Theoretically, we will apply state-of-the-art first-principles phonon simulations incorporating finite electric fields using the modern theory of polarization. In particular, we will investigate how the bonding nature of the wide-gap semiconductors is affected by the applied extremely electric fields, and how the crystal symmetry can be changed by the applied fields and in turn affect phonon scattering. Experimentally, we will incorporate the extreme external electric fields into laser-based thermal transport characterization techniques including time-domain thermal reflectance (TDTR) and transient thermal grating (TTG) to systematically examine the anisotropic effect regarding the crystallographic direction and the applied electric field directions. The expected outcomes of the proposed research will not only revolutionize our fundamental understanding of coupled charge and heat transport in wide-gap semiconductors, but also provide important design guidelines for optimizing thermal design of future power electronic devices based on wide-gap semiconductors.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 07, 2023
- Source ID
- FA95502210468
Entities
People
- Bolin Liao
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of California, Santa Barbara