Structural, chemical, and electrical parameters of Au/MoS2/n-GaAs metal/2D/3D hybrid heterojunction

Abstract

In this study, Au/MoS2/n-GaAs heterojunction is fabricated with single MoS2 layer and its structural, chemical and electrical parameters are investigated using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and measurement of current-voltage (I-V) characteristics at room temperature. XRD and XPS analysis results confirm the formation of MoS2 layer on the n-GaAs surface. The electrical properties of the Au/MoS2/n-GaAs heterojunction are compared with those of the Au/n-GaAs Schottky junction. Interestingly, the heterojunction possesses a higher barrier height, lower leakage current and higher rectification ratio, in comparison with the Schottky junction. The shunt resistance (RSh) and series resistance (RS) are also assessed for both the junctions. Moreover, the ideality factor (n), barrier height (Φb) and series resistance (RS) are evaluated using Norde, Cheung’s and surface potential (ΨS-V) plots and the results are well-matched. Furthermore, the current transport mechanism is analyzed based on the forward bias I-V data. Lastly, the Poole-Frenkel emission conduction mechanism is employed to control the reverse bias I-V behavior of both Au/n-GaAs Schottky junction and Au/MoS2/n-GaAs heterojunction. The results demonstrate that the Au/MoS2/n-GaAs heterojunction fabricated using a simple technique is suitable for high-quality electronic and optoelectronic device applications.