Flexible Counter Electrodes With A Composite Carbon/Metal Nanowire/Polymer Structure

Dye-sensitized solar cells（DSSCs）are new generation solar cells with a number of advantages,such as relatively low production costs,simple and environmentally friendly fabrication processes,and ease of large area fabrication.A DSSC typically consists of a photoanode,which is usually a dye-sensitized semiconductor oxide film on a glass substrate prepared with a conductive transparent film,an electrolyte containing a redox couple,typically I^-/I₃^-,and a counter electrode,which is mainly used to catalyze the redox reaction in the cell and to form a current circuit with the photoanode.A conventional counter electrode typically consists of a layer of platinum on top of a glass substrate prepared with a conductive transparent film.However,the geological reserves of platinum are very rare and the price is very expensive.Therefore,it is of great significance to develop new cheap and efficient counter electrode materials for reducing the cost of DSSC and promoting the large-scale application of DSSC.The thesis mainly focuses on:1.Preparation of metal nanowire/polymer flexible conductive substrate.The metal NW materials adopted include single-layer Ag NWs and Cu NWs,in addition to double-layer Ag NW/Cu NW and Cu NW/Ag NW configurations.The conductivity and light transmittance of the flexible substrates with different structures and different materials were compared.The metal nanowire/polymer substrate prepared in the experiment has a certain degree of bending resistance,which improves the stability of the dye-sensitized solar cell system under special scene conditions.2.The performance of the flexible carbon counter electrode prepared by three processes of doctor blade method,spray method and drop coating method was studied.The catalytic efficiency of the carbon counter electrode was compared,and the DSSCs was assembled and characterized.3.The carbon/silver nanowire/polymer counter electrode was prepared by the drop coating,whose efficiency was close to that of the carbon/FTO/glass counter electrode,and was much higher than that of carbon/ITO/PEN counter electrode.The improved carbon/copper nanowire/polymer counter electrode based DSSC achieved a high power conversion efficiency（PCE）of 4.01%.