Control of Ni/β-Ga2O3 Vertical Schottky Diode Output Parameters at Forward Bias by Insertion of a Graphene Layer.

Madani Labed,You Seung Rim,Nouredine Sengouga

doi:10.3390/nano12050827

Madani Labed, You Seung Rim + Show 1 more

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https://doi.org/10.3390/nano12050827

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Journal: Nanomaterials	Publication Date: Mar 1, 2022
Citations: 4	License type: CC BY 4.0

Affiliation: University of Biskra, Sejong University

Abstract

Controlling the Schottky barrier height () and other parameters of Schottky barrier diodes (SBD) is critical for many applications. In this work, the effect of inserting a graphene interfacial monolayer between a Ni Schottky metal and a β- semiconductor was investigated using numerical simulation. We confirmed that the simulation-based on Ni workfunction, interfacial trap concentration, and surface electron affinity was well-matched with the actual device characterization. Insertion of the graphene layer achieved a remarkable decrease in the barrier height (), from 1.32 to 0.43 eV, and in the series resistance (), from 60.3 to 2.90. However, the saturation current () increased from to (A/cm2). The effects of a graphene bandgap and workfunction were studied. With an increase in the graphene workfunction and bandgap, the Schottky barrier height and series resistance increased and the saturation current decreased. This behavior was related to the tunneling rate variations in the graphene layer. Therefore, control of Schottky barrier diode output parameters was achieved by monitoring the tunneling rate in the graphene layer (through the control of the bandgap) and by controlling the Schottky barrier height according to the Schottky–Mott role (through the control of the workfunction). Furthermore, a zero-bandgap and low-workfunction graphene layer behaves as an ohmic contact, which is in agreement with published results.

Highlights

Gallium oxide (Ga2 O3 ) is a new oxide semiconductor material with a long and rich history [1,2]
Its use in bipolar devices is limited to a heterojunction with other p-type materials such as NiO [8,9] and Cu2 O [10]. β-Ga2 O3 is mainly used in unipolar devices (SBD [4,11], MOSFET [12], Thin-Film Transistor (TFT) [13], and field emission [14] devices)
We demonstrated that a graphene monolayer can enhance the Schottky barrier diodes (SBD) outputs by increasWetunneling demonstrated that a graphenethe monolayer enhance

Summary

Introduction

Gallium oxide (Ga2 O3 ) is a new oxide semiconductor material with a long and rich history [1,2]. Ga2 O3 has six polymorphs: α, β, γ, δ, ε and k, with β-Ga2 O3 being the most stable [4]. It can be grown directly from the melt at a low cost and allows for large-scale production compared with. This material has a problem with developing a stable p-type [2,5–7]. Its use in bipolar devices is limited to a heterojunction with other p-type materials such as NiO [8,9] and Cu2 O [10]. The SBD device based on a UWBG semiconductor is of great interest and, aimed to improve the thermal stability and decrease the series resistance (Rs ), ideality factor (n), and leakage current. In addition to the above-mentioned characteristics, researchers aimed to develop SBDs with a controllable

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