Study On Patterned Preparation Of Silver Transparent Conductor And Its Properties

Transparent electrodes have both light transmission and electrical conductivity,which are essential for numerous applications including optoelectronic devices,transparent heaters,electronic skin,wearable smart devices and flexible touch screens.With the rapid development of flexible devices,transparent electrodes with flexibility becoming increasingly essential and necessary.Transparent conductors assembled by the metal ultrathin fibers such as Au,Ag and Cu have proven properties of high conductivity,high light transmittance and good mechanical flexibility.However,its primary limitation is the unrepeatable optoelectronic properties due to the disordered distribution of metal fibers.In this study,we report the in-situ direct writing of the silver microfiber pattern with high conductivity and transparency to attain a flexible transparent conductor.The silver network is composed of silver microfibers,which can be artificially designed and regularly patterned under the precise control of the fiber position and shape,which provided new ideas for regulation and optimization of metal fiber transparent electrodes.The main research results are as follows:(1)The silver microfiber was fabricated by direct writing using a solution containing Ag NO₃ and PVP.Ag⁺-contained precursor fiber was deposited on the collector which was accompanied by the evaporation of the solvent.Afterwards,the precursor fiber was converted into silver fiber under ultraviolet irradiation in an ambient environment.The effects of ultraviolet irradiation on the structure,morphology and electrical conductivity of silver fibers were studied.The results indicated that silver microfiber with high conductivity were fabricated after 4 h of UV irradiation.(2)Diverse silver microfiber patterns were designed and written on a mica substrate,such as parallel,regular hexagon,rhombus,quadrate,and more complicated ones like semicircle-linear and sinusoidal wave.Transparent electrodes have excellent flexibility and stability.When subjected to 1,000 cycles of large-angle bending,corrosion in solution of p H=3?11 for 7 days,and oxidation at 300°C for 1 hour,its conductivity remained unchanged.In addition,the silver pattern can survive to light up an LED light even after suffering a tape test,indicating great adhesion between fibers and substrate.(3)Both the transmittance and haze of silver transparent conductors can be well tailored by regulating the fiber pattern and the fiber diameter.The patterned silver network reached a sheet resistance as low as 2.0?sq^-1 at 89%transparency.The transparent electrodes own good electrothermal effect with power efficiency of 1.47 W cm^-2,indicating potential application in the field of flexible electrothermal devices.