J-V characteristics of the prepared inverted OPVs. Current density-voltage characteristics (a). External quantum efficiency of inverted OPVs with LZO as a cathode buffer layer (b). The evolution of EQE curves of LZO for three concentrations as a function of wavelength (c) 2 wt.%, (d) 10 wt.%, and (e) 30 wt.%.
Kim et al. Nanoscale Research Letters 2014 9:150 doi:10.1186/1556-276X-9-150