Enhanced photovoltaic effect derived from the regulation of Jahn–Teller distortion in a lattice compensation structure
Yaping Liu, Fei Guo, Bo Yang, Shifeng Zhao
Abstract
Larger remanent polarization and lower optical bandgap play crucial roles in the ferroelectric photovoltaic effect. However, they are always mutually conditioning for almost perovskite material based orbital hybridization theories. Here, we design a lattice compensation structure, in which Eu was incorporated to strengthen J–T distortion of Mn–O octahedral in BiFeO3–BiMnO3 solid solution films due to relieved degeneracy; in turn, the distortion compensates the lattice shrink derived from Eu doping. A narrow bandgap of 2.24 eV and a large remanent polarization of 93.7 μC/cm2 are achieved by lattice compensation modification. Compared with the film with an Eu doping concentration of 0.04, the open-circuit voltage and the short-circuit current of the film with 0.08 doping concentration are increased by 4.6 and 2.7 times, respectively, showing remarkable ferroelectric photovoltaic response. This work identifies an alternative strategy to enhance ferroelectric photovoltaic effects by regulating J–T distortion and lattice compensation.