CPOS Seminar: "Achieving Visible Light Semiconductor Optical Amplifiers on III- Nitrides"
Speaker: Arturo Juan, Graduate Student Researcher, Steven DenBaars Group, Materials Department, UCSB
Gallium nitride (GaN) is a wide bandgap semiconductor that is used in many electronic and optoelectronic devices such as transistors, LEDs, and Lasers. Semiconductor Optical Amplifiers (SOAs) are used to amplify signal for a targeted receiver and are primarily made for telecommunication applications in the infrared range (1.55µm). SOAs in the visible spectrum require sufficient gain, proper heat management, and long-term reliability. GaN can be alloyed with other group III materials and grown epitaxially via Metal-Organic Chemical Vapor Deposition (MOCVD) to achieve light emitting materials in the visible range, and for this work specifically blue (440 nm) and green (520 nm).
This work utilized bandgap engineering of thin group III-N films, on the order of 3 nm, from a semipolar bulk gallium nitride substrate. Deposition of films via MOCVD is a challenge for large scale production as there is a lack of large, cheap, and low-defect density substrates. Surface morphology, alloy composition, growth rates, and dopant incorporation are characterized with X-Ray Diffraction (XRD), Secondary Ion Mass Spectrometry (SIMS), and Atomic Force Microscopy (AFM) prior to processing as poor material quality will reduce the performance of devices. This talk will give a broad overview of inorganic semiconductor growth, processing, and characterization both at the research and industrial scale with the aim of utilizing visible light SOAs for telecommunication networks, and various sensing and signal processing applications.
