Enhanced photovoltaic property based on reduced leakage current and band gap in Nd-doped BiFeO3 films

Nd-doped BiFeO3 films were successfully fabricated on FTO glass substrate via sol-gel and spin-coating methods. Both the short circuit photocurrent density and the open circuit photovoltage of Nd-doped BiFeO3 film are clearly improved compared with the pristine BiFeO3 film, leading to more than 8-fold enhancement in power conversion efficiency for Bi0.9Nd0.1FeO3. The enhanced photovoltaic property benefits from reduced bandgap and leakage current after Nd-doping. The leakage current density of the Bi0.9Nd0.1FeO3 film is two orders lower than that of the pristine BiFeO3 film, which is the lowest in the reported BiFeO3 films. Nd-doped BiFeO3 film also shows the better ferroelectric and dielectric properties, which favored the practical application of BiFeO3 in multifunctional devices such as nonvolatile ferroelectric memories, novel photovoltaic devices and high frequency electrical components.