Science Technology

Academician of the Norwegian Academy of Science and Technology: AlGaN nanowire epitaxial UV LED using graphene substrate and transparent bottom electrode

From November 25th to 27th, with the special support of Shenzhen Longhua District Science and Technology Innovation Bureau, sponsored by the National Semiconductor Lighting Engineering Research and Development and Industry Alliance (CSA) and the Third Generation Semiconductor Industry Technology Innovation Strategic Alliance (CASA), The 16th China International Semiconductor Lighting Forum (SSLCHINA 2019) and 2019 International Third Generation Semiconductor Forum (IFWS 2019), jointly hosted by Shenzhen Third Generation Semiconductor Research Institute and Beijing McKenqiao New Material Productivity Promotion Center Co., Ltd., were held at the Shenzhen Convention and Exhibition Center.
On the morning of November 27, the “Solid State UV Device Technology” branch meeting was held as scheduled. Shanxi Zhongke Lu’an Ultraviolet Photovoltaic Technology Co., Ltd. and Zhongwei Semiconductor Equipment (Shanghai) Co., Ltd. jointly organized this session of the branch.
The third generation semiconductor materials have incomparable advantages in ultraviolet devices compared to other semiconductor materials, showing great application potential. The branch focuses on ultraviolet luminescent materials represented by aluminum gallium nitride and gallium nitride, ultraviolet detection materials represented by silicon carbide and gallium nitride, efficient quantum structure design and epitaxy, and key fabrication techniques for core devices such as light emitting diodes, lasers, photodetectors, etc.
Helge WEMAN, professor of Norwegian University of Science and Technology and academician of Norwegian Academy of Science and Technology, Lu Hai, professor of Nanjing University, Guo Haozhong, distinguished professor of Taiwan Jiaotong University, Hu Jianzheng, chief process engineer of Microelectronics Semiconductor Equipment (Shanghai) Co., Ltd., Wu Liang, professor of Shanghai University and president of Ultratrend Technologies Inc., Zhang Zihui, professor of Hebei University of Technology, Ni Ruxue, semiconductor research institute of Chinese Academy of Sciences, Internationally renowned experts such as Muhammad Nawaz SHARIF of Zhengzhou University, Gao Na of Xiamen University, and Wang Zhiyuan of Nanjing University participated in this meeting, striving to present the latest progress in materials, devices, packaging, and applications in the field of ultraviolet luminescence and detection at home and abroad. Kang Junyong, a professor at Xiamen University, and Wang Junxi, a researcher at the Semiconductor Institute of the Chinese Academy of Sciences and director of the Semiconductor Lighting Research and Development Center, co chaired the meeting.
Currently, deep ultraviolet LEDs made of AlGaN materials are mainly used for disinfection and sterilization. At the meeting, Helge WEMAN, a professor at the Norwegian University of Science and Technology and academician of the Norwegian Academy of Science and Technology, presented a theme report entitled “Al GaN nanowire epitaxial UV LED using graphene substrates and transparent bottom electrodes”, introducing the epitaxial growth technology of Al GaN nanowires on graphene substrates.
Since 2005, Professor Helge WEMAN has led a scientific research team at NTNU to study iii v group semiconductor nanowires and graphene for photoelectric applications. In June 2012, he participated in the founding of Crayonano AS and served as the Chief Technology Officer and Director.
He said that the epitaxial growth technology of AlGaN nanowires on graphene substrate has more advantages than existing thin film technologies. Due to the lack of sufficiently good transparent electrodes, high dislocation density, and the use of expensive AlN substrates and AlN buffer layers for most deep UV LEDs at this stage, their prices are high and their luminous efficiency is low. The first UV LED with flip chip structure for demonstration has been completed, which uses a double layer graphite structure. Its GaN/AlGaN nanowires are grown using MBE technology. This nanowire has high crystal quality, and there are no obvious defects and stress problems. Currently, the results of its research and detection indicate that the emission peak of this LED is not related to defective yellow light at 365 nm.