Recent Advances in Graphene Homogeneous p–n Junction for Optoelectronics

Graphene has been widely used as electrodes and active layers in optoelectronics due to its diverse excellent performances, such as high mobility, large thermal conductivity, and high specific surface area. Methodology for constructing p–n junction has become an important consideration in improving the performance of optoelectronic devices and broadening of its application in related fields. Currently, graphene-based p–n junctions have been explored and different structures have also been investigated. Herein, the recent progress on graphene homogeneous p–n junction is summarized, ranging from preparation of front-end materials (e.g., p- and n-type graphene) to building of planar and vertical p–n junctions. Furthermore, p–n junction via electrical modulation is described. The requirements for building the graphene homogeneous p–n junction, and the advantages and drawbacks of the different structures of the p–n junction are also discussed. Finally, a preferential technique to fabricate high performance p- and n-type graphene and building of the p–n junction is evaluated. This paper therefore provides an important indication on the future direction on the application of graphene in optoelectronics.