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.
@article{arxiv.1204.4461,
title = {Quantum Size Effects on the Chemical Sensing Performance of Two-Dimensional Semiconductors},
author = {Junghyo Nah and S. Bala Kumar and Hui Fang and Yu-Ze Chen and Elena Plis and Yu-Lun Chueh and Sanjay Krishna and Jing Guo and Ali Javey},
journal= {arXiv preprint arXiv:1204.4461},
year = {2012}
}