Phase engineering by strains in 2D semiconductors is of great importance for a variety of applications. Here, we present a study of strain induced ferroelectric (FE) transition on bismuth oxyselenide (Bi2O2Se) films, a high-performance (HP) semiconductor for next-generation electronics. Bi2O2Se is non-FE at ambient. Upon a loading force ≳400 nN, piezoelectric force responses exhibit butterfly loops on magnitude and 180o phase switching. By carefully ruling out extrinsic factors, these features are attributed to a transition to FE phase. The transition is further proved by the appearance of a sharp peak on optical second harmonic generation under an uniaxial strain. Fundamentally, solids with paraelectric at ambient and FE under strains are scarce. FE transition is discussed with the help of first-principle calculations and theoretical simulations. The switching of FE polarization acts as a knob for Schottky barrier engineering at contacts and serves as basis for a memristor with a huge switching ratio of 106. Our work endows a new degree of freedom to a HP electronic/optoelectronic semiconductor and the integration of FE and HP semiconductivity paving the way for multiple exciting functionalities, including HP neuromorphic computation and bulk piezophotovoltaic.
@article{arxiv.2303.02882,
title = {Achieving ferroelectricity in a centrosymmetric high-performance semiconductor by strain engineering},
author = {Mengqi Wu and Zhefeng Lou and Chen-Min Dai and Tao Wang and Jiaqi Wang and Ziye Zhu and Zhuokai Xu and Tulai Sun and Wenbin Li and Xiaorui Zheng and Xiao Lin},
journal= {arXiv preprint arXiv:2303.02882},
year = {2023}
}