(543g) Rapid Microwave Assisted Synthesis of Zinc Oxide Nano-Forest for Solar Cell Applications

Nanomaterials based photo-electro-chemical solar cells require high surface area as well as high electron transport quality to achieve good efficiency. Nanowires or hierarchical nanostructured arrays fulfill these two requirements. Synthesis of such complicated structures are conducted either using vapor phase deposition technique or lengthy wet-chemical route. We have synthesized Zinc oxide nano-forest structures on FTO glass using microwave assisted wet-chemical route. FESEM images revealed formation of highly ordered nanoforests structure. The main stem of zinc oxide nanowires have diameter around 100-150 nm and length about 10 µm, whereas the branch nanorods have diameter less than 50 nm and length about 1 µm. Instead of days for preparation using conventional wet-chemical routes, such nano-forest structures were prepared within 4 h using microwave assisted synthesis. XRD study revealed such nano-structures are highly crystalline c-axis oriented materials. Photo-sensitizer dye molecules were loaded on such semiconductor nanostructures to fabricate photo-anode for dye-sensitized solar cells. ZnO nanoforests based such solar cells showed enhanced photovoltaic efficiency.