Enhanced photovoltaic properties in bilayer BiFeO₃/Bi-Mn-O thin films

Abstract

We report an external solar power conversion efficiency of ∼1.43% in BiFeO3(BFO)/BiMnO3(BMO) bilayer thin films. Both films are epitaxially grown on (111) oriented niobium doped SrTiO3 (NSTO) single crystal substrates by pulsed laser deposition. By illuminating the BFO/BMO films under 1 Sun (AM 1.5 G), we found a remarkably high fill factor of ∼0.72, much higher than values reported for devices based on BFO or BMO alone. In addition, we demonstrate that the photocurrent density and photovoltage are tunable by changing the polarization direction in the BFO/BMO bilayer, as confirmed by the macroscopic polarization-voltage (P-V) hysteresis loop. This effect is described in terms of a more favorable energy band alignment of the electrode/bilayer/NSTO heterostructure junction, which controls photocarrier separation.

Enhanced UV-Vis Photodegradation of Nanocomposite Reduced Graphene Oxide/Ferrite Nanofiber Films Prepared by Laser-Assisted Evaporation

“…The thermal rise induced in the nanofiber/GO nanocomposite samples by laser irradiation during MAPLE deposition was simulated by solving the transient heat equation, using the finite element method, with COMSOL 5.3 Multiphysics software (COMSOL Inc., Stockholm, Sweden) [35][36][37][38][39][40][41][42].…”

“…Numerical simulations were performed in order to estimate the temperature evolutions during the MAPLE deposition, both for MFO and GO platelets, and to explain the presence of nanoparticles on the surface of the MFO, as well as MFO/GO hybrid composite films. To this aim, the transient heat equation was solved, employing the optical and thermophysical magnitudes reported in References [35][36][37][38][39][40][41][42]. The laser pulse duration was assumed to have a Gaussian shape (τ FWHM~5 ns), and distilled water solvent was supposed to have a negligible absorption at the wavelength of the laser radiation.…”

Applications of ferroelectrics in photovoltaic devices

“…Some studies addressed combinations of different ferroelectric materials [70][71][72][73][74][75]. Because various ferroelectric materials have different ferroelectric properties, light absorption properties, and photoconductivities combining different ferroelectric materials can not only yield efficient light absorption, but also enhance carrier charge separation through the interfacial Schottky barrier, which is of great importance for enhancing the performance of the device.…”

“…Because various ferroelectric materials have different ferroelectric properties, light absorption properties, and photoconductivities combining different ferroelectric materials can not only yield efficient light absorption, but also enhance carrier charge separation through the interfacial Schottky barrier, which is of great importance for enhancing the performance of the device. Chakrabartty et al [73] combined BFO and BiMnO3 (BMO) by growing BFO/BMO bilayer thin films sandwiched between ITO top electrodes and Nb (0.5%) doped SrTiO3 (NSTO) substrates. The fabricated device exhibited the PCE of~1.43%.…”

Characterization and Photovoltaic Properties of BiFeO3 Thin Films

“…In addition, photovoltaic properties of BiFeO 3 bulks, BiFeO 3 /semiconductor, and BiFeO 3 /ferroelectric heterostructures have been extensively investigated [6][7][8][9][10][11]. However, photovoltaic properties are sensitive to fabrication process, electronic structure, and interfacial condition.…”