Graphene-based transparent conductive electrodes for GaN-based light emitting diodes: Challenges and countermeasures.

Autor: Wang, Liancheng, Liu, Wei, Zhang, Yiyun, Zhang, Zi-Hui, Tiam Tan, Swee, Yi, Xiaoyan, Wang, Guohong, Sun, Xiaowei, Zhu, Hongwei, Volkan Demir, Hilmi
Zdroj: Nano Energy; Mar2015, Vol. 12, p419-436, 18p
Abstrakt: Graphene, with attractive electrical, optical, mechanical and thermal properties, is considered to be an ideal candidate for transparent conductive electrodes (TCEs) in many optoelectronic devices, including III-nitride based devices. However, high contact resistivity ( ρ c ) between graphene and GaN (especially p-GaN) has become a major challenge for graphene TCEs utilization in GaN-based light-emitting diodes (LEDs). Here, we analyzed the graphene/GaN contact junction in detail and reviewed the current research progress for reducing ρ c in graphene TCEs on GaN LEDs, including interface engineering, chemical doping and tunnel junction design. We also analyzed the current diffusion length for a single layer graphene (SLG) and multiple layer graphene (MLG) TCEs. Finally, to improve the fabrication process compatibility and simplicity with paramount reproduction, a method of directly growing graphene films on GaN by chemical vapor deposition (CVD) is proposed. We also give a short analysis on the reliability of graphene TCEs for GaN-based LEDs. It is believed that this is the ultimate solution for graphene TCEs application for GaN-based LEDs and others in general for other opto- and electrical devices. [ABSTRACT FROM AUTHOR]
Databáze: Supplemental Index