The Structure Optimization Based On TiO₂ Nanorod Arrays And Its Application In Solar Cells

The dye-sensitized solar cell?DSSC?has advantages of pollution-free,stable performance,controllable preparation conditions and so forth.It upsurges researches of new types of solar cells in the recent years,as well as the photo-anode materials of DSSC that is the key of the battery performance.When used as electrodes of DSSC,one-dimensional TiO₂ nano-arrays can improve the photoelectric conversion efficiency of the battery more significantly than TiO₂ nanoparticle porous membrance.However,because the specific surface area of one-dimensional TiO₂ array is limited,the dye adsorption is not high enough,and then causing a low light absorption coefficient.In this paper,we put forward a new way using traditional hydrothermal method to prepare one-dimensional TiO₂ nanorod arrays on FTO conductive glass,and then grow branched nanorod structures on the basis of TiO₂ nano-rod arrays.The phase structure and microstructure morphology,as well as the optical properties of both kinds of arrays were characterized.Besides,the nano-arrays were used as electrode materials of DSSC,organic/inorganic hybrid battery and quantum dot-sensitized solar cell.The photoelectric properties and interface modification of the batteries were discussed in detail.The main conclusions are as follows:1.The phase,morphology and optical property of TiO₂ nanorod arrays?NRAs?and branched TiO₂ nanorod arrays?B-NRAs?were compared.The diffraction peak?101?was remarkably enhanced of the B-NRAs than NRAs by X-ray diffraction,which indicates a preferential?101?growth of the branched structure.The UV absorption rate and the reflection rate of B-NRAs were both higher than that of the NRAs,which indicates that the branched structure can improve the light utilization efficiency.2.The NRAs and B-NRAs were soaked in N719 dye to form the photo-anode,and platinum?Pt?as the counter electrode,and then the dye sensitized solar cell was assembled.The photoelectric conversion efficiency of the B-NRAs DSSC was 2.01%,notably higher than the NRAs cell of 0.72%.In addition,the electrochemical impedance spectra?EIS?show that both the interface impedance and the charge lifetime of the B-NRAs photo-anode structure are higher than the NRAs structure.3.The NRAs and B-NRAs were soaked in N719 dye to prepare organic/inorganic hybrid solar cell packaged with polymer materials?P3HT and PCBM mixture liquid?.The photoelectric conversion efficiency of the two kinds batteries was tested.The efficiency of the hybrid cell made by B-NRAs was 1.37%,much higher than 0.84% of the NRAs.4.The NRAs and B-NRAs were modified through using cadmium sulfide?Cd S?quantum dots,and then hybrid cells were prepared,respectively.The ultraviolet absorption spectra show an expand absorption to 520 nm of the Cd S quantum dots cells.The photoelectric conversion efficiency of the B-NRAs hybrid cell reaches 2.13%,higher than the NRAs cell of 1.41%.Besides,the interface impedance and charge lifetime of the B-NRAs hybrid cell are both higher than those of the NRAs structure cell.