Structure and photovoltaic properties of ZnO nanowire for dye-sensitized solar cells

Aligned ZnO nanowires with different lengths (1 to approximately 4 μm) have been deposited on indium titanium oxide-coated glass substrates by using the solution phase deposition method for application as a work electrode in dye-sensitized solar cells (DSSC). From the results, the increases in length of zinc oxide (ZnO) nanowires can increase adsorption of the N3 dye through ZnO nanowires to improve the short-circuit photocurrent (J(sc)) and open-circuit voltage (V(oc)), respectively. However, the J(sc) and V(oc) values of DSSC with ZnO nanowires length of 4.0 μm (4.8 mA/cm(2) and 0.58 V) are smaller than those of DSSC with ZnO nanowires length of 3.0 μm (5.6 mA/cm(2) and 0.62 V). It could be due to the increased length of ZnO nanowires also resulted in a decrease in the transmittance of ZnO nanowires thus reducing the incident light intensity on the N3 dye. Optimum power conversion efficiency (η) of 1.49% was obtained in a DSSC with the ZnO nanowires length of 3 μm.