Photovoltaic Application of Rice Flake-Shaped ZnO Nanostructures

Rice flake-shaped zinc oxide nanocrystallites were synthesized through a polymer-assisted, one-step hydrothermal route with an average size of 200–600 nm. The role of polymer concentration in the evolution of the nanostructure was evaluated, and the material was characterized using x-ray diffraction, electron microscopy, x-ray photoelectron spectroscopy, and ultraviolet–visible (UV–Vis) spectroscopy. The two-dimensional (2D) nanoflakes were demonstrated as promising photoanode material for dye-sensitized solar cells. Compared with hydrothermally prepared zinc oxide nanoparticles, the rice flake-shaped crystallites exhibited higher dye loading and light-scattering ability, which elicited a substantial increase in the light conversion efficiency. Thus, a fabricated solar cell with an active area of of 0.25 cm2 was provided with a niobium pentoxide blocking layer through radio frequency magnetron sputter coating at the zinc oxide/transparent conducting oxide interface to boost the efficiency up to 7.09% from 5.72% under 1.5-AM conditions.