Electron Confinement at the Si/MoS sub(2) Heterosheet Interface

• Published in: Advanced materials interfaces Vol. 3; no. 10; p. np
• Main Authors: Molle, Alessandro, Lamperti, Alessio, Rotta, Davide, Fanciulli, Marco, Cinquanta, Eugenio, Grazianetti, Carlo
• Format: Journal Article
• Language: English
• Published: 01.05.2016
• Subjects: Channels; Distortion; Electronics; Gates; Molybdenum disulfide; Semiconductor devices; Silicon; Silicon substrates
• ISSN: 2196-7350; 2196-7350
• DOI: 10.1002/admi.201500619

The electronic band line-up between a uniform 2D silicon layer and a MoS sub(2) substrate is shown to result in a distortion of the MoS sub(2) bands. This effect is reflected in the admittance and electrical transport responses measured from the field-effect transistor incorporating the Si/MoS sub(2) heterosheet interface and fabricated from MoS sub(2) multilayer flakes on SiO sub(2)/Si super(++) substrates. In particular, the gate modulation of the capacitance curve and the observation of a double-peak feature in the transconductance profile make evidence of the built-in of two active channels in the transistor: one at the MoS sub(2)/SiO sub(2) interface and the other at the Si/MoS sub(2) heterosheet interface. The emergence of a gate modulated conductive channel at the Si/MoS sub(2) heterosheet interface is rationalized in terms of an effective electron accumulation at the Si/MoS sub(2) interface that is consistent with the electronic band bending deduced from high-resolution synchrotron radiation photoemission spectroscopy. A 2D silicon layer epitaxially grown on MoS sub(2) is shown to result in a distortion of the MoS sub(2) electronic bands in the proximity of the interface. This effect is responsible for the electron accumulation at the Si/MoS sub(2) heterosheet interface which gives rise to an additional gate modulated electronic channel in the transistor response.