Short circuit current as a function of time under on/off UV illumination cycles. The short circuit current as a function of time under on/off UV illumination cycles when a positive bias is applied to the ITO electrode (a) and when a negative bias is applied (b). Figures (c) and (d) are the corresponding energy band diagrams with respect to (a) and (b).
Chang et al. Nanoscale Research Letters 2012 7:231 doi:10.1186/1556-276X-7-231