In this work, we reported uniform layer-by-layer sublimation of black phosphorus under heating below 600 K. The uniformity and crystallinity of BP samples after thermal thinning were confirmed by Raman spectra and 2D Raman imaging. A uniform and crystalline bilayer black phosphorus flake with an area of 180 um^2 was prepared with this method. No micron scale defects were observed. The sublimation rate of BP was around 0.18 nm / min at 500 K and 1.5 nm / min at 550 K. Both room and high temperature Raman peak intensity ratio Si/A2g vs. BP thickness relations were established for in-situ thickness determination. The sublimation thinning method was shown to be a controllable and scalable approach to prepare few-layer black phosphorus.
@article{arxiv.1601.04103,
title = {Thermal Sublimation: a Scalable and Controllable Thinning Method for the Fabrication of Few-Layer Black Phosphorus},
author = {Weijun Luo and Rui Yang and Jialun Liu and Yunlong Zhao and Wenjuan Zhu and Guangrui and Xia},
journal= {arXiv preprint arXiv:1601.04103},
year = {2017}
}
Comments
New data have been included in this version, which were presented at the MRS fall meeting 2016