Charge Carrier Transport Behavior and Dielectric Properties of BaF2:Tb3+ Nanocrystals

Xiaoyan Cui; Tingjing Hu; Huangyu Wu; Junkai Zhang; Lihua Yang; Xin Zhong; Xiaoxin Wu; Jingshu Wang; Xuefei Li; Jinghai Yang; Chunxiao Gao

doi:10.3390/nano10010155

Charge Carrier Transport Behavior and Dielectric Properties of BaF₂:Tb³⁺ Nanocrystals

Nanomaterials (Basel). 2020 Jan 16;10(1):155. doi: 10.3390/nano10010155.

Authors

Affiliations

¹ Key Laboratory of Functional Materials Physics and Chemistry of the Ministry of Education, National Demonstration Center for Experimental Physics Education, Jilin Normal University, Siping 136000, China.
² State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, China.

Abstract

The charge carrier behavior and dielectric properties of BaF₂:Tb³⁺ nanocrystals have been studied by alternating current (AC) impedance spectroscopy. The electron and ion coexist in the transport process. The F^- ion's contribution to the total conduction increases with the doping concentration up to 4% and then decreases. Tb doping leads to the increase of defect quantities and a variation of charge carrier transport paths, which causes the increase of the ion diffusion coefficient and the decreases of bulk and grain boundary resistance. When the Tb-doped concentration is higher than 4%, the effect of deformation potential scattering variation on the transport property is dominant, which results in the decrease of the ion diffusion coefficient and increases of bulk and grain boundary resistance. The conduction properties of our BaF₂:Tb³⁺ nanocrystals are compared with previous results that were found for the single crystals of rare earth-doped BaF₂. Tb doping causes increases of both the quantity and the probability of carrier hopping, and it finally leads to increases of BaF₂ nanocrystals' permittivity in the low frequency region.

Keywords: dielectric behavior; electrical properties; ion conduction; nanocrystals.