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论文类型： 期刊论文

发表时间： 2017-09-14

发表刊物： JOURNAL OF CHEMICAL PHYSICS

收录刊物： Scopus、SCIE、EI、PubMed

卷号： 147

期号： 10

页面范围： 104709

ISSN号： 0021-9606

摘要： Among various two-dimensional (2D) materials, monolayer group-III monochalcogenides (GaS, GaSe, InS, and InSe) stand out owing to their potential applications in microelectronics and optoelectronics. Devices made of these novel 2D materials are sensitive to environmental gases, especially O-2 molecules. To address this critical issue, here we systematically investigate the oxidization behaviors of perfect and defective group-III monochalcogenide monolayers by first-principles calculations. The perfect monolayers show superior oxidation resistance with large barriers of 3.02-3.20 eV for the dissociation and chemisorption of O-2 molecules. In contrast, the defective monolayers with single chalcogen vacancy are vulnerable to O-2, showing small barriers of only 0.26-0.36 eV for the chemisorption of an O-2 molecule. Interestingly, filling an O-2 molecule to the chalcogen vacancy of group-III monochalcogenide monolayers could preserve the electronic band structure of the perfect system-the bandgaps are almost intact and the carrier effective masses are only moderately disturbed. On the other hand, the defective monolayers with single vacancies of group-III atoms carry local magnetic moments of 1-2 mu(B). These results help experimental design and synthesis of group-III monochalcogenides based 2D devices with high performance and stability. Published by AIP Publishing.