Fig. 1. (a) Schematic diagram and (b) XRD patterns of the Au-BFO nanocomposite films.

Fig. 2. XPS core level spectra of (a) Au 4f, (b) Bi 4f, (c) Fe 2p, (d) O 1s for the Au-BFO nanocomposite films with 0.5 mol% Au.

Fig. 3. Surface SEM images of the Au-BFO nanocomposite films with (a) 0, (b) 0.25 mol%, (c) 0.5 mol%, (d) 1 mol%, (e) 3 mol% Au; (f) the variation of grain size with Au content.

Fig. 4. (a) UV-vis absorption spectra and (b) plot of (αhν)² as a function of hν for the Au-BFO nanocomposite films with 0, 0.25 mol%, 0.5 mol%, 1 mol%, and 3 mol% Au.

Fig. 5. Out-of-plane PFM phase images of the Au-BFO nanocomposite films with (a) 0 mol%, (b) 0.25 mol%, (c) 0.5 mol%, (d) 1 mol%, (e) 3 mol%; (f) the variation of the ratio of P_up with Au content.

Fig. 6. Current density vs. voltage (J-V) characteristics of the Au-BFO nanocomposite films (a) in dark; lnJ vs. V^1/2 curves fitted using the Schottky emission and lnJ vs. lnV curves fitted using space-charge limited current for the (b) positive and (c) negative branches.

Fig. 7. (a) Photovoltaic (J-V) curves of the Au-BFO nanocomposite films with 0, 0.25 mol%, 0.5 mol%, 1 mol%, and 3 mol% Au, and (b) variation of open-circuit voltages and short-circuit photocurrent densities with Au content.

Fig. 8. Time-dependence of photocurrent density (J-T) curves of the Au-BFO nanocomposite films with 0, 0.25 mol%, 0.5 mol%, 1 mol%, and 3 mol% Au under the short-circuit condition.