Detecting Band Profiles of Devices with Conductive Atomic Force Microscopy

TL;DR

This paper introduces a contact-mode conductive atomic force microscopy technique to map the nanometer-scale band profiles of electronic devices like MoS2 transistors at room temperature, revealing detailed band bending near edges.

Contribution

It develops a novel contact-mode STS method that overcomes limitations of traditional techniques, enabling high-resolution band profile mapping of devices.

Findings

Discovered 0.6 eV band bending within 18 nm of MoS2 edges

Achieved nanometer resolution mapping at room temperature

Demonstrated applicability to various electronic devices

Abstract

Band profiles of electronic devices are of fundamental importance in determining their properties. A technique that can map the band profile of both the interior and edges of a device at the nanometer scale is highly demanded. Conventional scanning tunneling spectroscopy (STS) can map band structure at the atomic scale, but is limited to the interior of large and conductive samples. Here we develop a contact-mode STS based on conductive atomic force microscope that can remove these constraints. With this technique, we map the band profile of MoS$_2$ transistors with nanometer resolution at room temperature. A band bending of 0.6 eV within 18 nm of the edges of MoS$_2$ on insulating substrate is discovered. This technique will be of great use for both fundamental and applied studies of various electronic devices.