Wenliang Wang

South China University of Technology, China

Title: Group-III nitride epitaxial materials and optoelectronic devices grown on Si substrates for visible light communication

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Biography

Wenliang Wang is a full professor at School of Material Science and Technology in South China University of Technology, focusing on the research of GaN heterogeneous epitaxial materials and devices. During the past five years, he has presided over a number of national/provincial projects such as the National Natural Science Foundation of China top-level projects, the National Key R&D Program subject tasks, and the National Defense Science and Technology Innovation Special Zone Projects. 

Abstract

In recent years, with the rapid development of the communication field, the commercialization of visible light communication (VLC) is accelerating. Thanks to its high confidentiality, fast transmission rate and strong anti-electromagnetic interference, VLC has a wide range of application prospects and has been considered as the core of next-generation wireless communication technology. Group-III nitride epitaxial materials and optoelectronic devices grown on Si substrates demonstrate considerable potential for applications in VLC, due to the exceptional optoelectronic properties and stability of group-III nitrides, as well as the mature technology and low cost of Si substrates. However, group-III nitride epitaxial materials grown on Si substrates still face the problem of high dislocation density due to large lattice and thermal mismatch, and corresponding optoelectronic devices encounter challenges in the regulation of carrier transport, which impede their potential applications in VLC. In response to these scientific challenges, our team has put forth a solution that encompasses the full range of material epitaxial growth, structure modulation and device fabrication. Firstly, a two-step growth technique was proposed which combines low-temperature pulsed laser deposition (PLD) with high-temperature metal-organic chemical vapor deposition (MOCVD). High-quality GaN epitaxial films have been synthesized on Si substrates through this technique with the dislocation density of 107 cm-2,  which is an improvement over the internationally reported level of 108 cm-2. Secondly, several heterostructures of different materials combined with group-III nitride films have been designed and optimized to realize the regulation of carrier transport for the preparation of high-performance GaN-based optoelectronic devices including InGaN/PdO-based photodetectors, and graphene/GaN-based ?LEDs, etc. On the basis of improving device performance, the above devices have been applied to VLC systems and verified their feasibility.