[101 ̅0] Oriented Hybrid 3D ZnO Nanowalls Architecture with Enhanced Dye-Sensitized Solar Cells Performance
The orientation and morphology of metal-oxide nanomaterials have a major impact on their properties and applications. Here, we developed a hybrid 3D ZnO nanowall (NWL) architecture onto transparent conducting oxide substrates via a low-temperature solution process. As grown hybrid 3D ZnO NWLs architecture are perfect single crystals with a wurtzite structure, and orientation along the [101 @#x0305;0] direction is confirmed using transmission electron microscopy. Such architecture has unique combination of high surface-area with cage-like pores, which was applied as electron transporting material (ETM) in a porphyrin-based dye-sensitized solar cells. The devices exhibited maximum photocurrent density of 11.86 mA.cm-2, power conversion efficiency of 4.08% and which was higher than the pristine ZnO nanowall (2.76%) or nanowire (1.92 %) devices; due to the orientation and surface area. The faster orientation and surface area a faster charge transport rate than the mesoporous films and  oriented ZnO nanostructure. The unique crystallographic orientation of the 3D ZnO NWL architecture opens up a novel configuration for designing high‒performance optoelectronic devices and expands their application fields.