Influence of Sputtering Temperature of TiO2 Deposited onto Reduced Graphene Oxide Nanosheet as Efficient Photoanodes in Dye-Sensitized Solar Cells

Abstract

Renewable solar energy is the key target to reduce fossil fuel consumption, minimize global warming issues, and indirectly minimizes erratic weather patterns. Herein, the authors synthesized an ultrathin reduced graphene oxide (rGO) nanosheet with ~47 nm via an improved Hummer’s method. The TiO2 was deposited by RF sputtering onto an rGO nanosheet with a variation of temperature to enhance the photogenerated electron or charge carrier mobility transport for the photoanode component. The morphology, topologies, element composition, crystallinity as well as dye-sensitized solar cells’ (DSSCs) performance were determined accordingly. Based on the results, FTIR spectra revealed presence of Ti-O-C bonds in every rGO-TiO2 nanocomposite samples at 800 cm–1. Besides, XRD revealed that a broad peak of anatase TiO2 was detected at ~25.4° after incorporation with the rGO. Furthermore, it was discovered that sputtering temperature of 120 °C created a desired power conversion energy (PCE) of 7.27% based on the J-V plot. Further increase of the sputtering temperature to 160 °C and 200 °C led to excessive TiO2 growth on the rGO nanosheet, thus resulting in undesirable charge recombination formed at the photoanode in the DSSC device.

Zinc oxide/graphene nanocomposite as efficient photoelectrode in dye‐sensitized solar cells: Recent advances and future outlook

“…Recently, the modification of TiO 2 nanostructure‐based material has received considerable attention as a photoelectrode for DSSCs to enhance the PCE 12,23,24 . As a comparison, zinc oxide (ZnO) has been commonly used as a photoelectrode owing to its broader bandgap energy (~3.37 eV) than TiO 2 , which facilitates the transfer of photoexcitation electrons into the CB of ZnO with great dye aggregation control on the ZnO surface 25‐28 .…”

“…11,22 Recently, the modification of TiO 2 nanostructurebased material has received considerable attention as a photoelectrode for DSSCs to enhance the PCE. 12,23,24 As a comparison, zinc oxide (ZnO) has been commonly used as a photoelectrode owing to its broader bandgap energy (~3.37 eV) than TiO 2 , which facilitates the transfer of photoexcitation electrons into the CB of ZnO with great dye aggregation control on the ZnO surface. [25][26][27][28] Moreover, ZnO also exhibits a stable physical-chemical property, high charge carrier transport (115-155 cm 2 /Vs), and large exciton binding energy (60 eV), 29 which is favorable for efficient charge mobility and probably reduces the charge recombination rate in DSSCs.…”