Symposium EP08—Ultra-Wide-Bandgap Materials and Devices
Research in the field of ultra-wide-bandgap semiconductors has continued to expand in recent years. Notably, materials such as gallium oxide, diamond, and aluminum nitride with bandgaps exceeding that of gallium nitride (3.4 eV) constitute the next frontier in semiconductor physics research. In many cases, the fundamental properties of these materials are not well known, for example the physics of high-energy carrier scattering processes responsible for electrical breakdown. Further, fundamental challenges such as the synthesis of high-quality substrates, effective impurity doping during epitaxial growth, the formation of low-resistance ohmic contacts, and the integration of insulators with such semiconductors (which are close to being insulators themselves) present challenges in terms of device fabrication. Thus, while such materials hold great promise for applications ranging from optoelectronic emitters and detectors, to more compact and efficient energy converters, to higher-power high-frequency amplifiers, to advances in quantum information science, many materials issues must be resolved before such ultra-wide-bandgap semiconductors can reach maturity and have a significant impact. This symposium will cover a broad range of topics related to the materials science and device physics of ultra-wide-bandgap materials, with an eye towards the applications of the materials that are driving research in the field. Topics of current interest in the traditional wide-bandgap materials will also be considered. For example, the lack of an effective means to perform selective-area doping of gallium nitride has to date imposed severe limitations on the fabrication of vertical-architecture power switching devices, and the efficiency droop problem continues to hinder solid-state lighting despite its successful and widespread commercialization.