Controllable microstructure tailoring for regulating conductivity in Al-doped ZnO ceramics

Qianying Sun (1, 2, 3) , Guorong Li (1, 3) , Tian Tian (1, 3) , Zhenyong Man (1, 3) , Liaoying Zheng (1, 3) , Maud Barré (2) , Jens Dittmer (2) , François Goutenoire (2) , Abdel Hadi Kassiba (2)

1 State Key Laboratory of High Performance Ceramics and Superfine Microstructure [Shanghai Institute of Ceramics]
2 IMMM - Institut des Molécules et Matériaux du Mans
3 IOS - Institute of semiconductors [Chinese Academy of Sciences - Beijing]

Structural and electrical behavior of Al2O3 doped ZnO-based ceramics were investigated as function of the aluminum doping ratios under reducing sintering atmosphere (N2+CO). With Al2O3 doping from 0.1 mol% to 0.55 mol%, the electrical conductivity increases firstly to a maximum (1.52 × 105 S·m−1) at 0.25 mol%, and then decreases gradually. The increased conductivity is explained by the formation of shallow donors as AlZn-Zni complexes with doping to 0.25 mol%. As Al2O3 doping further increasing to 0.55 mol%, ZnAl2O4 spinel phase and more ZnO-ZnO grain boundaries are formed, hindering charge carriers transport, to decrease charge carrier mobility, thus to decrease the conductivity of ZnO ceramics. Therefore, the AlZn-Zni complexes, grain boundaries and ZnAl2O4 spinel can be adjusted by doping different Al2O3 amount, thus the carriers’ concentration and their mobility are optimized to increase the conductivity. Our work, as a fundamental research, is of great significance to control conductivity by regulating Al2O3 doping.

Mots clés: ZnO ceramics; Al doping; Grain boundaries; Secondary phases; Electrical behavior

Domaines: Matière Condensée [cond-mat]; Science des matériaux [cond-mat.mtrl-sci]

Qianying Sun, Guorong Li, Tian Tian, Zhenyong Man, Liaoying Zheng, et al.. Controllable microstructure tailoring for regulating conductivity in Al-doped ZnO ceramics. Journal of the European Ceramic Society, 2020, 40 (2), pp.349-354. ⟨10.1016/j.jeurceramsoc.2019.10.011⟩. ⟨hal-02462826⟩