Prof. Sitar founded the WideBandgaps research laboratory that is focusing on bulk and thin film growth, characterization, and device development in wide bandgap semiconductors: GaN, AlN, and their alloys. He has pioneered the III-nitride MBE process through the design of a unique ECR plasma source, developed, patented, and commercialized a process for growth of AlN crystals, which is currently the only commercial high-quality AlN crystal growth process in the world (commercialized by HexaTech, Inc.), developed, patented, and commercialized epi-ready wafers and device layer growth processes on AlN wafers, which are the basis for high-efficiency deep-UV lasers and light emitting diodes, invented and patented a process for growth of III-nitride lateral polar structures via MOCVD and proposed and demonstrated novel devices based on this invention, which include lateral p-n diodes, low contact-resistance field effect transistors, quasi phase matched structures for optical frequency doubling, and superjunction-based devices.