Fig. 4: Effect of illumination on ferroelectric polarization.
From: Multiferroic oxide BFCNT/BFCO heterojunction black silicon photovoltaic devices
a Changes of P-V loop with different power densities of the light source. b Effect of illumination and field direction on ferroelectricity of BFCNT/BFCO heterojunction. c Evolution of ferroelectric domains under different conditions. d Schematic of both energy band alignment and the corresponding changes of the built-in polarization with and without illumination
