Growth Of 1-D Well-aligned ZnO Nanorod Arrays And Its Application

As the ordered ZnO nanostructure has been envisioned to enhance performance of various technologically important devices such as short-wavelength lasers,Dye-sensitized solar cell,the interest in synthesis of well-aligned ZnO nanowires or nanorods on substrates keeps growing.In the paper,we use two-step method to grow Well-aligned ZnO nanorods on transparent electric glass substrates.Firstly,we deposited a layer of ZnO film on the substrate as the nanoseed film,and then used the Chemical solution deposition method to grow the ZnO nanorod arrays.According to study the relationship between the nanoseed films and the order of the ZnO nanorods,we can see that the nanoseed films decrease the crystal lattice unmatching,and determine the reflection of the ZnO nanorod arrays.We also discover that the nanorod arrays have better order when we play the substrate vertically than levelly.Therefore,we get the optimized procedure to synthesis the well-aligned ZnO nanorod arrays.Characterized the ZnO nanorod arrays we can see that SEM demonstrated that most of the nanorods are wurtzite crystal structure,and are vertical to the substrate.The average diameter of rods is around 40 nm,and the length is about micrometer.In the XRD pattern,the two peaks are indexed as(002)and(004)of the wurtzite structure of ZnO,indicating that the nanorods are preferentially oriented in the c-axis direction. Absorption spectra of the nanorod arrays show our sample exist strong UV absorbtion and ZnO essence absorption peak is at 371.5 nm.The photoluminescence spectra of ZnO nanorod arrays have been studied,the excitation spectra of the nanorod arrays have a strong and narrow peak at 387 nm with FWHM smaller than 30 nm and a weak blue peak band around 468 nm,compared the intensities of the two peaks,we cen see that the ZnO nanorod arrays have good quality.We also use the well-aligned ZnO nanorod arrays in dye sensitized solar cells to research the PV performance and reseive some useful results.It is expected that a direct conduction pathway from the point of electron-hole pair generation to the collecting electrode would significantly improve the electron transport efficiency.We grow the ZnO nanorod arrays on ITO and FTO substrates respectively,both of the effective areas of the two solar cells are 1 cm~2.The parameters of the solar cells which based the nanorod arrays growed on FTO substrates are:Isc=5.79 mA/cm~2,Voc=0.52 V,η= 0.84%;on ITO substrates are:Isc =1.33 mA/cm~2,Voc=0.44 V,η=0.16%. Compared the characters of the two solar cells,we have better characters growing the ZnO nanorod arrays on FTO substrates than on ITO substrates.The mechanism of the method synthesizing well-aligned ZnO nanorod arrays in our paper is similar to the hydrothermal,but our experiment carries in open solution system,which does not need the sealed kettle and avoids the high-pressure and seal conditions.Compared to the hyderthomal,our method is more safely,and less limited to the reaction container,it will be more convenient and economic in synthesizing large-scale well-aligned ZnO nanorod arrays.