Silicon Thin Film Solar Cell Based On ZnO Nano-array

In the dissertation,A type of n-ZnO/p-Si heterojunction solar cell based on ZnO nano-arrays is proposed. Its structure is: the FTO or AZO substrates and ZnO seed layer, Zn O nano-arrays, silicon thin film and metal electrodes. Concrete this dissertation, the preparation methods and Physical characterization of the solar cell is studied, by changing the technological conditions and preparation parameters of the solar cells structure related performance. The main preparation process of the solar cell as follows: the first step is pre-fabricated ZnO seed layer by sol-gel method on the FTO or AZO substrate, then the highly consistent of ZnO nano-arrays are prepared on the ZnO seed layer by chemical Solution growth method; Secondly the p-type silicon thin films can be deposited by PECVD; lastly the layer of metal is plated on the silicon thin films by vacuum coatin., then it forms n-Zn O/p-Si heterojunction solar cell.Compared with other structure of solar cell, the silicon thin film nucleated and grew directly on ZnO nanorods in this solar cell structure, forming the structure of silicon thin film coated ZnO nano-arrays. This structure design can makes the ZnO nano-arrays contacting entirely with silicon thin films. The transfer of carrier can be effectively in the ZnO nano-arrays. It will improve the conversion efficiency of solar cells. Inthis dissertation, polycrystalline thin films are prepared by metal Al induced crystallization, Al atoms can act as acceptor in Si and donor in ZnO. Not only to avoid changes in battery performance preparation or element doping process in the use of mutual diffusion causes, and can effectively improve the formation of PN junction, the battery open circuit voltage.Our laboratory has successfully prepared this cell structure of the silicon thin film fully coated ZnO nano-array. In the experiment, the concentration, reaction time changes of precursor ZnO growth in the body of the Zn2+ regulation, preparation of N-type ZnO nano-array morphology; through the P-type silicon thin film parameters changing preparation of silicon thin film of silane concentration, reaction temperature and deposition time, the doped concentration, the preparation of coated ZnO nano-array. By using X-ray diffraction, Ultraviolet-visible spectrophotometer, Scanning electron microscope, Raman scattering spectroscopy and Four-probe method for the preparation of the crystal structure of each layer of thin film solar cells, optical properties, surface morphology and electrical properties were explored.