Graphene Schottky diodes: An experimental review of the rectifying graphene/semiconductor heterojunction

Abstract

In the past decade graphene has been one of the most studied material for several unique and excellent properties. Due to its two dimensional nature, physical and chemical properties and ease of manipulation, graphene offers the possibility of integration with the exiting semiconductor technology for next-generation electronic and sensing devices. In this context, the understanding of the graphene/semiconductor interface is of great importance since it can constitute a versatile standalone device as well as the building-block of more advanced electronic systems. Since graphene was brought to the attention of the scientific community in 2004, the device research has been focused on the more complex graphene transistors, while the graphene/semiconductor junction, despite its importance, has started to be the subject of systematic investigation only recently. As a result, a thorough understanding of the physics and the potentialities of this device is still missing. The studies of the past few years have demonstrated that graphene can form junctions with 3D or 2D semiconducting materials which have rectifying characteristics and behave as excellent Schottky diodes. The main novelty of these devices is the tunable Schottky barrier height, a feature which makes the graphene/semiconductor junction a great platform for the study of interface transport mechanisms as well as for applications in photo-detection, high-speed communications, solar cells, chemical and biological sensing, etc. In this paper, we review the state-of-the art of the research on graphene/semiconductor junctions, the attempts towards a modeling and the most promising applications.

Vertically Illuminated, Resonant Cavity Enhanced, Graphene–Silicon Schottky Photodetectors

“…We get Φ B ∼0.46eV and η ∼11. These are in the range of previously reported values (0.41< Φ B <0.47 and 2< η <30) for SLG/Si Schottky diodes [34][35][36][37][38][39]. By fitting the I-V curve in reverse bias we get the SBH dependence on applied reverse voltage and find ∆Φ B up to∼80meV at -10V, Fig.5b.…”

“…Graphene/Si Schottky PDs at 1550nm have been demonstrated both in free-space [34] and guided mode configurations [35,36], with R ext up to 10mA/W and 0.37A/W respectively. In these devices, a single layer graphene (SLG) acts as electrode in contact with Si, forming a Schottky junction with rectifying characteristics [37][38][39]. In general, graphene is an attractive material for photonics and optoelectronics [40][41][42][43].…”

“…∆Φ B (V ) is typically dominant in reverse bias because of the higher potential drop on the Schottky junction, resulting in a more pronounced barrier-lowering Schottky effect [8,61] and SLG Fermi level shift [37,38,61]. On the other hand, in forward bias the potential drop is limited by the built-in voltage (V bi <1V) [8], so that ∆Φ B (V ) can be neglected and Φ B ∼ Φ B0 .…”

Fundamentals of Chemical Vapor Deposited Graphene and Emerging Applications

“…The exciton dissociation can be achieved to obtain a photovoltaic action by creating a suitable barrier height in the graphene/Si heterojunction [92][93][94]. Recent studies show more than 10% conversion efficiency of CVD graphene/n-Si Schottky junction solar cells [95].…”

“…GaN is one of the most promising wide bandgap semiconductors for applications in optoelectronic and other electronic devices such as light-emitting diodes, laser diodes, solar cells, and high-electron-mobility transistors [95][96][97][98][99]. The transparency of metal oxide conductors is poor in the UV and near UV region, which affects the photodetectors efficiency and brightness of LEDs.…”