The ferroelectric photovoltaic spectral response regulated by band-gap in BiFe0.9Cr0.1O3 films

•The photovoltaic spectral response can be regulated by the band gap.•The photovoltaic responses have shown a noteworthy red-shift towards the visible wavelength.•The photovoltaic response shifting is attributed to the rhombohedral distortion.

BiFe0.9Cr0.1O3 solid solution films have been prepared via the solution-gelation technique. The structure, ferroelectricity, optical band-gap, and photovoltaic spectral response were investigated. It shows that the photovoltaic spectral responses for BiFe0.9Cr0.1O3 films shift towards visible region compared with the pure BiFeO3 films. The halfway points of the full width at half-maximum are detected at 378 nm and 420 nm, closely corresponding to the measured band-gap of BiFeO3 and BiFe0.9Cr0.1O3 films. Thus photovoltaic behaviors are attributed to the narrower band-gap derived from the rearrangement of molecular orbital and rhombohedral distortion. The present work provides an available way of controlling photovoltaic response of ferroelectric films and accelerating its application in light sensors, light drivers and ferroelectric photovoltaic cells.

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