The effect of vacancy defects on the electromechanical properties of monolayer NiTe2 from first principles calculations

• Published in: Physical Chemistry Chemical Physics
• Main Author: Yeoh K.H.; Chew K.-H.; Chang Y.H.R.; Yoon T.L.; Ong D.S.
• Format: Article
• Language: English
• Published: Royal Society of Chemistry 2022
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85143981726&doi=10.1039%2fd2cp05102h&partnerID=40&md5=a43f83f9776180d29b0b5e84ec582509

The electromechanical properties of monolayer 1-T NiTe2 under charge actuation were investigated using first-principles density functional theory (DFT) calculations. Monolayer 1-T NiTe2 in its pristine form has a work area density per cycle of up to 5.38 MJ m−3 nm upon charge injection and it can generate a strain and a stress of 1.51% and 0.96 N m−1, respectively. We found that defects in the form of vacancies can be exploited to modulate the electromechanical properties of this material. The presence of Ni-vacancies can further enhance the generated stress by 22.5%. On the other hand, with Te-vacancies, it is possible to improve the work area density per cycle by at least 145% and also to enhance the induced strain from 1.51% to 2.92%. The effect of charge polarity on the contraction and expansion of monolayer 1T-NiTe2 was investigated. Due to its excellent environmental stability and good electromechanical properties, monolayer NiTe2 is considered to be a promising electrode material for electroactive polymer (EAP) based actuators. © 2022 The Royal Society of Chemistry.