Direct Visualization and Manipulation of Tunable Quantum Well State in Semiconducting Nb2SiTe4

TL;DR

This study uses ARPES and STM/STS to directly visualize and manipulate quantum well states in Nb2SiTe4, revealing tunable properties that could enhance electronic and optical device performance.

Contribution

It demonstrates the direct visualization and surface manipulation of QWSs in Nb2SiTe4, a novel approach for engineering quantum states in semiconductors.

Findings

QWSs can be directly visualized in Nb2SiTe4.

Potassium dosage effectively tunes QWS position and splitting.

Nb2SiTe4 shows potential for quantum state engineering in devices.

Abstract

Quantum well states (QWSs) can form at the surface or interfaces of materials with confinement potential. They have broad applications in electronic and optical devices such as high mobility electron transistor, photodetector and quantum well laser. The properties of the QWSs are usually the key factors for the performance of the devices. However, direct visualization and manipulation of such states are in general challenging. In this work, by using angle-resolved photoemission spectroscopy (ARPES) and scanning tunneling microscopy/spectroscopy (STM/STS), we directly probe the QWSs generated on the vacuum interface of a narrow band gap semiconductor Nb2SiTe4. Interestingly, the position and splitting of QWSs could be easily manipulated via potassium (K) dosage onto the sample surface. Our results suggest Nb2SiTe4 to be an intriguing semiconductor system to study and engineer the QWSs, which has great potential in device applications.