CPM Seminar

When molecular beam epitaxy meets nanowires

Songrui Zhao

Department of Electrical and Computer Engineering
McGill University

Since the birth of molecular beam epitaxy in late 1960s, it has evolved into a material synthesis technique for both fundamental science and device development for modern information and communication technologies. On the other hand, low-dimensional materials, due to their fundamentally different structural, electrical, and optical properties, compared to their bulk counterparts, can provide a new avenue to solve challenges in device development and further create device technologies that did not exist before. In this seminar, I will discuss the molecular beam epitaxy of group-III nitride nanowire heterostructures, and I will show that using such low-dimensional group-III nitrides by molecular beam epitaxy, quite a few underlying material challenges for III-nitride photonic devices can be greatly addressed, e.g., p-type doping. This further leads to devices that were not possible previously, such as AlN LEDs with turn-on voltages only limited by the bandgap energy, contrary to the AlN thin film LEDs that requires 20-30 V turn-on voltages; and electrically injected AlGaN deep UV lasers at 239 nm, whereas such short wavelength electrically pumped lasers were not accessible before with conventional thin film technologies.