Effect of solution processed graphene oxide/nickel oxide bi-layer on cell performance of bulk-heterojunction organic photovoltaic

We report the solution processed graphene oxide (GO), NiOx and GO/NiOx bi-layer used as an anode interfacial layer in organic bulk-heterojunction solar cells. The bulk-heterojunction solar cells using GO, NiOx and GO/NiOx bi-layer exhibited the conversion efficiency of 2.33%, 3.10% and 3.48%, respectively. The cell efficiency is correlated with the matching of energy levels between ITO, hole transport layer and P3HT and thus a well-matched stack layer of ITO/GO/NiOx/P3HT:PCBM/LiF/Al shows the best cell efficiency of 3.48% with the JSC of 8.71 mA/cm2, VOC of 0.602 V and FF of 66.44%.

Schematic device structure, energy diagram, and J–V characteristics of device with GO/NiOx as a HTL.Figure optionsDownload as PowerPoint slideHighlights
► NiOx and GO were introduced by solution process as a hole transport and electron blocking layer.
► The device with GO/NiOx bi-layer exhibits an enhanced cell performance compared with a single NiOx or GO.
► Improved cell efficiency is correlated with the well-matched energy levels between ITO, GO/NiOx and P3HT.
► Best cell efficiency of device with GO/NiOx shows 3.48% which is 49% increase in efficiency compared to the OPV without HTL.