We report a scalable approach to synthesize a large-area (up to 4 mm) thin black phosphorus (BP) film on a flexible substrate. We first deposited a red phosphorus (RP) thin-film on a flexible polyester substrate, followed by its conversion to BP in a high-pressure multi-anvil cell at room temperature. Raman spectroscopy and transmission electron microscopy measurements confirmed the formation of a nano-crystalline BP thin-film with a thickness of around 40 nm. Optical characterization indicates a bandgap of around 0.28 eV in the converted BP, similar to the bandgap measured in exfoliated thin-films. Thin-film BP transistors exhibit a field-effect mobility of around 0.5 cm2/Vs, which can probably be further enhanced by the optimization of the conversion process at elevated temperatures. Our work opens the avenue for the future demonstration of large-scale, high quality thin-film black phosphorus.
@article{arxiv.1508.05171,
title = {Synthesis of thin-film black phosphorus on a flexible substrate},
author = {Xuesong Li and Bingchen Deng and Xiaomu Wang and Sizhe Chen and Michelle Vaisman and Shun-ichiro Karato and Grace Pan and Minjoo Larry Lee and Judy Cha and Han Wang and Fengnian Xia},
journal= {arXiv preprint arXiv:1508.05171},
year = {2015}
}