Prof. Shengjun Zhou
School of Power and Mechanical Engineering, Wuhan University, China
Speech Tilte: Boosting efficiency of GaN-based light-emitting diodes
Abstract: GaN-based light-emitting diodes (LEDs) have attracted considerable interest for their applications in solid state lighting, automotive front lighting, and full-color displays because of their high luminous efficiency, low energy consumption, long operation lifetime, and broad spectral range spanning from ultraviolet to red wavelengths. The light extraction efficiency of GaN-based blue/green/ultraviolet 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 extracting micro/nano-structure designs for boosting efficiency of GaN-based blue/green/ultraviolet LEDs. Exploratory research in developing efficient light extracting micro/nano-structures, such as surface texturing, patterned sapphire with silica array, reflective electrode, wavy sidewalls, nano-prisms, embedded air void microstructure, distributed Bragg reflector (DBR), polymer grating, laser stealth dicing, and nanoscale Ni/Au wire gird, will be discussed. Moreover, the recent development in flip-chip LED, vertical LEDs, and Mini/Micro-LEDs will also be introduced.
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 National Youth Talent Support Program, distinguished Young Scholar of Hubei province, Chutian Scholar of Hubei province, and Luojia Young Scholar of Wuhan University. He has published more than 70 papers and holds over 20 patents. He is Co-chair of the Organizing Committee for IEEE ICEPT 2016 conference. He served as committee member for many conferences.