Controllable Synthesis Of Silver Nanowire And Performance In Its Transparent Conductive Electrode Application

Silver nanowire can be used to fabricate transparent electrode that owns both excel ent opto-electronic properties and flexibility,and thus becoming the most promising transparent conductive material of the new generation to replace ITO-glass.Theoretic studies show that silver nanowires should have an average diameter of smal er than 30 nm and an aspect ratio of more than 800 to fabricate high perfomance transparent electrodes.The purpose of this dissertation is to synthesis ultrathin silver nanowires and to fabricate high-performance transparent electrode.The certain conditions to synthesis wires of this different size are studied and the transparent electrode was fabricated,optimized and characterized.According to our research,the one-pot polyol method is facile to control the size of silver nanowires.Seeding condition,growing resistance and rate,secondary seeding are factors that influence the synthesis of ultrathin nanowires.The reaction system and relative experimental parameters are studied systematical y for synthesizing high aspectratio silver nanowires and through it silver nanowires with an average length range of 0.04 to 40?m and a diameter range of 40 to 100 nm is obtained.The effects of several kinds of halide salts on seeding and growing during synthesizing nanowires are studied extensively.The relationship between halide salt,seed size and product size is clarified.Silver nanowires of an average size of 21?m/26 nm and an aspect ratio over 800 were yielded by adding NaCl/KBr hybrid nucleant,which is enough to fabricate high-performance transparent electrodes.The decrease of reacton activity by chloride ion and the control to the size of silver seeds are key factors for obtainning ultrathin nanowires.Silver nanowire dispersion(without resin)and coating ink(with resin)were prepared on the basis of separation and dispersing,and transparent electrodes with glass or PET substrate were fabricated by spin coating.The films have sheet resistances of 17.6?/sq(glass)and 29.5?/sq(PET)respectively when the transmittance of them are 90%.The films made by coating ink have equivalent optoelectronic properties and could maintain their conductivity after tape-test.Post-treatments like washing,heating,pressing and agent reduction could further optimizing the optoelectronic properties of the conductive films.The basic reason for improving the optoelectronic properties in post-treatments above is to decrease the contact resistance at nanowire network junctions.The film on glass could reach a sheet resistance of as low as 10?/sq at a transmittance of 90% after heating,which is notably better than commercial ITO/glass.The adhesion force to substrate of films on PET is significantly increased after heating.The adhesion force to substrate of films on PET is also largely improved(the sheet resistance of the film increased less than 10% after several times of tape test)after the transparent electrode is coated with binding resin.