ABSTRACT
A light-emitting diode (LED) is a solid state lighting source that can convert electrical energy into optical radiation. Traditionally, the electrodes material of LED is indium tin oxide (ITO). However, both indium and tin are limited resources, which increase the price of LEDs. In order to improve the performance of graphene-based LED, Kim et al. used plasma-assisted metal-catalyst-free synthesis for graphene/GaN-based LEDs. Moreover, when polycrystalline graphene was directly integrated into GaN-based LEDs through PECVD, in situ formation of ohmic contact was found between graphene and p-GaN. In order to improve the performance of graphene-based LEDs, scientists tried to combine graphene with other materials such as nanoclusters. In PSL array and graphene hybrid LEDs, one problem is that the direct contact of graphene with the inorganic semiconductors generally leads to high injection barriers that degrade performance and frustrate reliable operation. Due to current spreading layers (CSLs) used in LEDs, the performance of LEDs has significantly improved.
