Photovoltaic properties of Aurivillius Bi4NdTi3FeO15 ceramics with different orientations

C-axis preferentially and randomly oriented Bi4NdTi3FeO15 (BNTF) ceramics were prepared by molten salt synthesis and conventional solid-state reaction methods, respectively. The ceramics with different orientations all exhibit Aurivillius structure containing four perovskite layers and the Lotgering factor f of c-axis preferentially oriented BNTF prepared by molten salt synthesis was calculated to be 0.865. BNTF powders show two absorption edges due to the electron excitations not only from valence band (VB) to Ti 3d conduction band (CB) but also to Fe e(g) CB. The ferroelectric and photovoltaic properties of BNTF ceramic samples were investigated. The ferroelectric performance of randomly oriented ceramic sample is better than that of c-axis preferentially oriented one. Significant photovoltaic effect was observed in both ceramic samples. Compared with the ceramic with c-axis preferred orientation, the randomly oriented ceramic exhibits a larger photocurrent J(SC) and a smaller photovoltage V-OC, which was discussed from the grain alignment in the two ceramics and the anisotropy of the crystal structure. The present work provides a new way to control photovoltaic properties of lead-free Bi5Ti3FeO15 (BTF) based compounds and accelerates their application in ferroelectric photovoltaic (FEPV) and energy fields. (C) 2019 Elsevier B.V. All rights reserved.