The photovoltaic spectral response regulated by band gap in Zr doped Bi4Ti3O12 thin films

Abstract

The pure and Zr doped Bi4Ti3O12 thin films have been prepared via the solution–gelation technique. The phase structure, optical band gap, and photovoltaic spectral response were investigated in detail. It shows that the photovoltaic responses of the short-circuit current for Zr doped Bi4Ti3O12 thin films have shown a noteworthy red-shift behavior compared with the pure Bi4Ti3O12 thin films. The halfway points of the full width at half-maximum are detected at 469 and 514 nm, closely corresponding to the measured band gap for the thin films. Thus photovoltaic response behavior is attributed to octahedral distortion and optical band gap narrowing. The present work provides an available way on controlling photovoltaic properties of Bi4Ti3O12 based thin films and accelerating its application in light sensors, light drivers and ferroelectric photovoltaic cells.