Growth and characterization of AlGaN based UV-LED structures by metal organic vapor phase epitaxy

AlGaN based UV-LEDs emitting at 340 nm were grown on c-sapphire (0001) by Metal Organic Vapor Phase Epitaxy (MOVPE) method and characterized in this work. Generation of defects related to large lattice mismatch between c-plane sapphire substrate and AlGaN layers is the most important adversity in growing AlGaN based UV-LEDs. AlN buffer optimization is carried out with nucleation, nitridation and desorption parameters in order to reduce defects. At the same time a work is performed on n type and p type layers as well as electron blocking layers to get better diode characteristics and combine more carriers in active region. Thickness of p type doped cladding layers with p contact metals were decreased in order to reduce strong internal absorption. In summary, a strong and sharp Electro-luminescence (EL) peak observed at 339 nm with 8mA injection current. FWHM of EL peak is determined as 13,7 nm