My research interest is GaN-based material epi-growth and p-n junction device fabrication. GaN material attracted scientists' attention more than 30 years ago. However, it was until early 1990s that GaN-based material showed commercial promise to fabricate a real device. GaN has very promising applications in many areas especially extremely conditions such as high temperature, high power/high frequency, et cetera. It is its unique properties that attract so many attentions. My research involves several issues including the material growth, n-type and p-type doping, device fabrication and characterization. The research tool I use is called MOCVD (Acronym for Metal Organic Chemical Vapor Deposition). The MOCVD system is Aixtron Aix-200 model. It wasn't designed for nitrides growth. However, I added some new features to enable it to reach high temperature that is preferable for nitride growth. So far, I have partially achieved GaN growth optimization. The material I grow can guide the wave! My next goal is to make p-type doped GaN. P-type GaN so far is still a challenge to GaN community. My long-term goal is to fabricate some real p-n junction device structures on my material. Please check this page periodically as more results will come later. (Joe)