Realization of Electron Antidoping by Modulating the Breathing Distortion in BaBiO3

• Published in: Nano letters 2021-05, Vol.21 (9), p.3981-3988
• Main Authors: Cao, Hui, Guo, Hongli, Shao, Yu-Cheng, Liu, Qixin, Feng, Xuefei, Lu, Qinwen, Wang, Zhongping, Zhao, Aidi, Fujimori, Atsushi, Chuang, Yi-De, Zhou, Hua, Zhai, Xiaofang
• Format: Article
• Language: English
• Subjects: absorption; antidoping; ASTRONOMY AND ASTROPHYSICS; BaBiO3; band gap; breathing distortion; doping; electrical conductivity; main group oxides; oxides; oxygen vacancies; physiology
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/acs.nanolett.1c00750

The recent proposal of antidoping scheme breaks new ground in conceiving conversely functional materials and devices; yet, the few available examples belong to the correlated electron systems. Here, we demonstrate both theoretically and experimentally that the main group oxide BaBiO3 is a model system for antidoping using oxygen vacancies. The first-principles calculations show that the band gap systematically increases due to the strongly enhanced Bi–O breathing distortions away from the vacancies and the annihilation of Bi 6s/O 2p hybridized conduction bands near the vacancies. Our further spectroscopic experiments confirm that the band gap increases systematically with electron doping, with a maximal gap enhancement of ∼75% when the film’s stoichiometry is reduced to BaBiO2.75. These results unambiguously demonstrate the remarkable antidoping effect in a material without strong electron correlations and underscores the importance of bond disproportionation in realizing such an effect.