Effect of testing conditions on the photovoltaic performance of ZnO-based dye sensitized solar cells

Dye-sensitized solar cells based on vertically-aligned ZnO nanorod, were analyzed at different conditions. Stability tests showed an improvement on solar conversion efficiency between ∼20% (1000 W/m2) and ∼50% (1800 W/m2). This behavior was ascribed to the physisorption/chemisorption of the N-719 dye on the ZnO due to UV light. Studies at different temperatures proved that the performance of the cells can double when decreasing temperature from 72 ∘C to room temperature. An increase on the efficiency and decrease in FF was observed when light intensity is increased. IPCE analyses were used to monitor the stability of the solar cells with time.