Fig. 4

(a) I-V curves of ITO/ETL/BCP or BCP:sodium caseinate/Ag configuration for both pristine and sodium caseinate doped BCP layers (b) J–V curves of electron-only devices, (c) Topography images pristine and sodium caseinate doped doped BCP (d) I–V curves through KPFM measurements of pristine and sodium caseinate doped BCP layers.