Photoconductivity and photo-detection response of multiferroic bismuth   iron oxide
  We report visible light detection with in-plane BiFeO3 (BFO) thin films grown on pre-patterned inter-digital electrodes. In-plane configured BFO film displayed photocurrents with a 40:1 photo-to-dark-current ratio and improved photo-sensing ability for >15000 s (4 hrs) under small bias voltage (42V). Nearly sixty percent of the photo-induced charge carriers decay in 1.0 s and follow a double-exponential decay model. At 373 K the effect of light does not significantly increase the dark current, probably due to reduced mobility. Sub-bandgap weak monochromatic light (1 mw/cm2) shows one fold increase in photo-charge carriers. 
Avneesh Anshul, Hitesh Borkar, Paritosh Singh, Prabir Pal, Sunil S   Kushvaha, Ashok Kumar
cond-mat.mtrl-sci