Quantum Size Effects on the Chemical Sensing Performance of Two-Dimensional Semiconductors

TL;DR

This study explores how quantum size effects in two-dimensional InAs semiconductors significantly enhance gas sensor performance, with thinner membranes showing up to 100 times better response due to electron quantization.

Contribution

It demonstrates the impact of quantum confinement on sensor sensitivity, providing experimental and modeling evidence for thickness-dependent performance in 2D semiconductor gas sensors.

Findings

Sensor response increases up to 100x as thickness decreases from 48 to 8 nm.

Quantum confinement alters charge carrier properties, enhancing surface interaction sensitivity.

Thickness scaling trend explained by electron quantization effects.

Abstract

We investigate the role of quantum confinement on the performance of gas sensors based on two-dimensional InAs membranes. Pd-decorated InAs membranes configured as H2 sensors are shown to exhibit strong thickness dependence, with ~100x enhancement in the sensor response as the thickness is reduced from 48 to 8 nm. Through detailed experiments and modeling, the thickness scaling trend is attributed to the quantization of electrons which favorably alters both the position and the transport properties of charge carriers; thus making them more susceptible to surface phenomena.