Enhancement of Photovoltaic Performance of Dye-Sensitized Solar Cells Using Hierarchical Zinc Oxide/Tin Oxide (ZnO/SnO2) Nanocomposites Synthesized via Hydrothermal Method
Abstract
The study reports heterostructured photoanodes for dye-sensitized solar cells (DSSC) based on zinc oxide/tin oxide (ZnO/SnO2) nanocomposites. These nanocomposites have been synthesized via a simple two-step hydrothermal method. The varied amount of SnO2 has been incorporated into ZnO to fabricate ZnO/SnO2 heterostructures. The as-synthesized heterostructures and pristine oxides when investigated for their morphological studies, they revealed a variety of morphologies such as nanoparticles, nanoflakes-like structures nanopetals, etc. These hierarchical morphologies of the nano-heterostructures were found to be advantageous for solar cell performance. Further, the photoanodes of DSSC fabricated with ZnO/SnO2 nanocomposites were characterized by JV measurements and exhibited enhancement in photovoltaic properties as compared to pristine ZnO and SnO2. Optimized ZnO/SnO2 nanocomposite exhibited nearly three times higher photovoltaic efficiency than pristine ZnO-based DSSC. A high-power conversion efficiency (PCE) of around 2.42 % was obtained at 1 sun for ZnO/SnO2 nanocomposite with a 1:5 Zn: Sn molar ratio. The Photovoltaic parameters such as current density (Jsc), open circuit voltage (Voc), and fill factor are 0.66V, 7.65mA/cm2, and 0.48 respectively. The enhancements in the device performance can be ascribed to increasing surface area due to hierarchical morphology and reduction in recombination of charge carriers leading to enhanced mean electron lifetime.