Tuning power factors of two-dimensional Bi2O2Se nanoplates through vacancy engineering. (September 2021)

• Record Type: Journal Article
• Authors: Wu, Z.; Wang, Y.; Liu, G.; Yang, X.; Wei, T.; Zhang, H.; Zhou, J.; Zhu, J.
• Is Part Of: Materials today energy. Volume 21(2021)
• Publication Date: 2021-09
• Subjects: Thermoelectric -- Band engineering -- Self-doping -- 2D materials; Energy development -- Periodicals; Energy industries -- Periodicals; Power resources -- Periodicals; Energy policy -- Periodicals; Energy development; Energy industries; Energy policy; Power resources; Electronic journals; Periodicals; 621.042
• DOI: 10.1016/j.mtener.2021.100810
• Languages: English
• ISSNs: 2468-6069

Abstract

Abstract: Bi2 O2 Se, as a novel two-dimensional (2D) material, is attracting much attention owing to unique electrical and optoelectrical properties. Particularly, 2D Bi2 O2 Se with high mobility and a suitable bandgap has been predicted to be a promising thermoelectric material. Here, we performed systematic investigation of thermoelectric properties of 2D Bi2 O2 Se through both experimental measurements and theoretical calculations. It is found that the post-growth 2D Bi2 O2 Se nanoplates exhibit semi-metallic behavior because of existence of oxygen vacancies. Furthermore, vacancy engineering through annealing, which effectively tunes the concentration of oxygen vacancies, can significantly enhance the Seebeck coefficient of 2D Bi2 O2 Se (30–90 μV/K) and the power factor (1–2.7 μW/cm/K 2 ), competitive as an air-stable oxide thermoelectric material. Our results not only demonstrate the promising power factor of 2D Bi2 O2 Se, but also provide a general and alternative strategy of vacancy engineering for tuning the thermoelectric properties of low-dimensional materials. Graphical abstract: Thermoelectric properties of two-dimensional Bi2 O2 Se nanoplate are systematically investigated for the first time through both calculation and experiment. Vacancy engineering by annealing can effectively tune the thermoelectric properties of these nanoplates from metallic to semiconducting, and lead to enhanced Seebeck coefficient and power factor. Image 1 Highlights: Thermoelectric properties of 2D Bi2 O2 Se nanoplate are systematically investigated through both calculations and experiments. High surface/volume ratio of 2D nanoplates offer unique advantage for vacancy engineering through annealing processes. Vacancy engineering can effectively tune the thermoelectric properties of 2D nanoplates through band modulations.