Reduction of Schottky Barrier Height at Graphene/Germanium Interface with Surface Passivation

Abstract

Fermi level pinning at metal/semiconductor interfaces forbids a total control over the Schottky barrier height. 2D materials may be an interesting route to circumvent this problem. As they weakly interact with their substrate through Van der Waals forces, deposition of 2D materials avoids the formation of the large density of state at the semiconductor interface often responsible for Fermi level pinning. Here, we demonstrate the possibility to alleviate Fermi-level pinning and reduce the Schottky barrier height by the association of surface passivation of germanium with the deposition of 2D graphene.

In-Depth Analysis on Self Alignment Effect of the Fermi-Level Using Graphene on Both n- and p-Type Semiconductors

“…However, its applicability as a universal integrated contact has not yet been comprehensively investigated. Previously reported research does not provide any detailed analysis of Gr contacts with semiconductors, and some studies even suggest the opposite results, leaving the role of Gr unclear. ,,− …”

Single-Layer Graphene/Germanium Interface Representing a Schottky Junction Studied by Photoelectron Spectroscopy

“…Therefore, this type of contact provides an excellent opportunity to study the physical phenomena occurring at the interface formed by 2D and 3D materials. Moreover, it also offers a convenient platform for investigating electronic properties and transport mechanisms that have not yet been elucidated from the point of view of fundamental knowledge [35][36][37][38][39][40][41]. An approach based on ab initio calculations was also used to study the interface involving 2D materials for predicting the structural and electronic properties, as well as the thermal stability of these interfaces [42,43].…”

“…It also enables the use of Ge's high-carrier mobility, near-infrared absorption coefficient, and compatibility with mainstream Si technology. Consequently, increasing the Schottky potential barrier's height using the graphene/Ge junction is the key to reducing the dark current and improving the sensitivity and signal-to-noise ratio in this class of devices [40][41][42][44][45][46].…”