Prof. Shengjun Zhou
Prof. Shengjun Zhou
Wuhan University, China
Title: High efficiency GaN-based light-emitting diodes
GaN-based light-emitting diodes (LEDs) have been considered as a candidate of next generation solid-state light sources for replacement of general lighting sources such as florescent lamps and due to their environmentally friendly properties and long lifetime. The light extraction efficiency of GaN-based LEDs is relatively low due to total internal reflection (TIR) of the generated light at the nitride-air interface resulting from their very different refractive indices. This talk will outline the emerging challenges in light out-coupling structure designs for highly efficient LEDs. Exploratory research in developing efficient light out-coupling structures, such as V-pits surface texturing, patterned step-like ITO, reflective current blocking layer, patterned cone-shaped sapphire substrate, wavy sidewalls, embedded air void, distributed Bragg reflector (DBR), micro/nano polymer grating, laser stealth dicing, nanoscale Ni/Au wire gird and flip-chip technology, will be discussed. 
Shengjun Zhou received the Ph.D. degree from Shanghai Jiao Tong University, Shanghai, China, in 2011. He is a Professor at Wuhan University. His current research interests lie in the areas of GaN-based LEDs, photonics and semiconductors, nanoimprint lithography and direct laser writing with applications in electronic and photonic devices. He is well known as an industrial technologist. Prior to joining Wuhan University, he was a CTO at Quantum Wafer Inc. from 2011 to 2014, focusing on the development of high brightness GaN-based LEDs. He was a research fellow at University of Michigan, Ann Arbor, from 2014 to 2015. He received many academic awards including Chutian Scholar and Luojia Young Scholar of Wuhan University. He has published more than 50 papers and holds 10 patents.