An investigation of the dye-sensitized solar cell performance using graphene-titania (TrGO) photoanode with conventional dye and natural green chlorophyll dye

Development of innovative low-cost and efficient DSSCs (dye-sensitized solar cell) device for solar energy conversion is essential. In this present study, the performance of DSSCs based on graphene-titania (TrGO) photoanode using conventional N719 (synthetic dye) and natural green chlorophyll dye (organic dye) were extensively studied, analysed and discussed. TrGO was successfully synthesized via one step sol precipitation peptization technique using titanium (IV) isopropoxide (TTIP) and reduced graphene oxide (rGO) as starting materials. It was found that TrGO-2 exhibited the highest photocurrent generation among samples regardless of dye type. DSSCs device fabricated using N719 dye showed 9.15 mA cm−2 of photocurrent with 3.95% efficiency whereas DSSCs device using natural chlorophyll green dye exhibited photocurrent density of 3.43 mA cm−2 with 0.67% efficiency. From the Tauc plot, band gap was narrowed from 3.17 eV of TiO2 to 2.78 eV of TrGO considering the graphene extended the absorption range of the film to the visible light region. The main reason was associated with the better surface contact of the TiO2 dopants with the rGO film resulting in a lower charge transfer resistance.