Anchored Cu2O nanoparticles on graphene sheets as an inorganic hole transport layer for improvement in solar cell performance

We study the effect of dependent Cu2O nanoparticles (NPs) to the graphene oxide sheets (DCG), on the performance of dye-sensitized solar cells and the electron lifetime. Aqueous Cu2O nanoparticles were prepared and anchored on the graphene sheets by arc discharge method and then used as a coating layer to increase the electron lifetime in photoanode. Results show that open-circuit voltage of the cell increases up to 0.7V by use of DCG/TiO2 as aphotoanode. In addition, performance characterization of the prepared cells by current density versus voltage (J-V) measurements show that the fill factor (FF) and power conversion efficiency () increase from =1.5% and FF=52% for TiO2 photoanode (as a reference) to =3.48% andFF=65% for DCG/TiO2 photoanode. The electron lifetime of the prepared samples was measured by open-circuit voltage-decay measurement (OCVD). Results show that the open circuit voltage and the electron-hole lifetime increase as well for TiO2 /DCG photoanode. To explore the effect of electron-hole concentration on thecell performance, we perturbed the electron-hole generation rate by three different illuminations and then measured the OCVD. Results show that the timescale of power decay for TiO2/DCG photoanode in high illumination is about 150s.