Highly efficient hybrid solar cell using ZnO nanorods and assessment of changes in cell performance by varying the growth period

Zinc oxide nanorod arrays (ZnO NRs) were grown from ZnO seed-coated substrates in an aqueous solution by using the hydrothermal method for different growth periods varying from 5 min to 1 hour. The influence of the growth period of the ZnO nanorods on photovoltaic applications was studied in detail. Experimental results showed that utilization of the nanorod arrays lead to an enhanced the cell performance by increasing of light absorption and creation of a vertical direction for electron transport in the solar cells. A power conversion efficiency of 3.33% with an opencircuit voltage of V (OC) = 0.58 V, a short-circuit current of J (SC) = 10.05 mA/cm(2) and a fill factor of FF = 54.35% was achieved for solar cells based on ZnO NRs with growth period of 20 min. Such solar cells with an optimal growth period are effective in light trapping, which leads to a significant enhancement in the absorption of light, and thereby, show an obvious increase in the power conversion efficiency.