Vertically Aligned ZnO/In_xS_y Core–Shell Nanorods for High Efficient Dye-Sensitized Solar Cells

Abstract

Innovative vertically aligned ZnO/In x S y nanorod (NR) electrodes were prepared by successive ion layer adsorption and reaction (SILAR) technique. The In x S y shell layer was deposited on top of ZnO NR electrodes of two di®erent lengths, $ 1:6 m and $ 3:2 m. Two sulfur contents on the In x S y shell layer with di®erent layer thicknesses were analyzed. These electrodes were fully characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray di®raction spectroscopy (XRD), Energy-dispersive x-ray spectroscopy (EDS), Infrared spectroscopy (FT-IR), x-ray photoelectron spectroscopy (XPS) and ultraviolet photoemission spectroscopy (UPS) and then applied in dye-sensitized solar cells (DSC). Power conversion efciency of 2.32% was observed when a low-sulfur content In x S y shell layer was applied in comparison to the stoichiometric In 2 S 3 shell layer (0.21%) or the bare ZnO NRs (0.87%). In the case of low sulfur content, a shell layer of In(OH) x S y or/and In(OH) 3 is formed as observed by the presence of -OH observed by FTIR analyses. The presence of higher amounts of hydroxide groups modi¯es the bandgap and work function of the In x S y shell and facilitates dye adsorption, increasing the¯nal solar cell performance.

Photoconversion efficiency of In2S3/ZnO core-shell heterostructures nanorod arrays deposited via controlled SILAR cycles

“…Ming Li et al [36] modified the electronic structure properties of ZnO by In 2 S 3 nanosheet arrays using the atomic layer deposition method. Compared to the abovementioned methods for the In 2 S 3 /ZnO heterostructures synthesis, the SILAR approach is easier for producing the In 2 S 3 /ZnO core-shell heterostructures nanorod arrays (IZCSHNRAs) [37].…”