Research On Manufacturing And Performance Of Metal Mesh Transparent Electrode Based On Ultrafast Laser Direct Writing

Transparent electrodes(TEs)have received extensive attention in recent decades due to their unique photoelectric properties.These TEs can be basic materials in many applications,such as solar cells,light emitting diodes(LEDs),smart windows and touch screens.Recent years,as a kind of TEs,transparent conductive oxide(TCO)films,represented by tin-doped indium oxide(ITO)films and fluorine-doped tin oxide(FTO)films,have dominated the application fields so far.However,they suffer from several critical drawbacks,including film brittleness,high price,low abundance and low optical transmittance.Therefore,the research on new transparent electrodes is imperative.As a new type of TE,the metal mesh-based TE has attracted more and more researchers'attention due to its excellent electrical and optical performance.However,the existing preparation methods have some disadvantages,such as high manufacture costs,restrictions on the choice of metals and substrate materials and poor repeatability.Thus,this paper proposes a maskless,controllable and economical method to produce high performance metal mesh-based TEs based on ultra-fast laser direct writing technology and combined with physical deposition method.Which achieves the preparation of metal mesh transparent electrode on various substrates and achieves excellent performance.By this method,the transparent electrode with metal mesh on various substrates was prepared and excellent properties were obtained.(1)The fluorine-doped tin oxide(FTO)film on a glass substrate was etched by using a femtosecond pulsed laser with a wavelength of 1030 nm,a repetition rate of 19.12 MHz and a pulse duration of 262 fs.The effects of laser fluence and scanning speed on the quality of the groove etched on the FTO film surface were systematically studied,trying to improve the groove quality.The results indicated that in order to obtain high quality grooves,a balance needed to be achieved between laser fluence and scanning speed.The scanning speed had a considerable influence on the groove width,and the best groove quality(groove width was7.92?m)was determined at the scanning speed of 3000 mm/s and the laser fluence of 0.055J/cm~2.(2)The femtosecond pulsed laser with a wavelength of 1030 nm,a repetition frequency of 19.12 MHz,and a pulse width of 262 fs was used to etch mesh grooves on the PVP/FTO substrates,and then the Ag mesh transparent electrodes were prepared on the FTO substrates by magnetron sputtering.The influence of different laser fluences,scanning speeds and Ag mesh heights on the photoelectric performance of Ag mesh transparent electrodes based on FTO substrates were systematically studied.The results indicated that the best performance was determined at the scanning speed of 2200 mm/s and the laser fluence of 0.050 J/cm~2,when the mesh height was 600 nm.In this case,the commutation quality factor Fo M reached 420.36,which achieved a good photoelectric performance.Furthermore,the effect of the Ag mesh height on the electrode properties was also investigated.The results showed that when the height of Ag mesh reached 2500 nm,the performance of metal mesh TE was optimal,and its Fo M reached 2576.46.(3)A femtosecond laser was used to etch the mesh grooves on the PVP/glass substrate,and then the Ag mesh transparent electrodes were prepared on the glass substrate.The effects of scanning speeds and laser fluences on the photoelectric performance of the Ag mesh transparent electrode on the glass substrate were systematically studied.And the influences of different Ag mesh pitches and heights on the photoelectric performance of the Ag mesh transparent electrode were also studied.The results showed that the best laser repetition frequency was 330 k Hz,the scanning speed was 200 mm/s and the laser fluence was 6.15J/cm~2.The Ag mesh TE fabricated based on glass substrate with the mesh height of 500 nm and mesh pitch of 0.8 mm had a light transmittance of 89.29%,a sheet resistance of 1.24?/sq and its commutation quality factor Fo M reached 2608.59.Afterwards,it was found that when the Ag mesh height was 2000 nm,the fabricated Ag mesh TE based on the glass substrate had very excellent comprehensive photoelectric properties,with a light transmittance of 88.79%,a sheet resistance down to 0.44?/sq and a Fo M value of 6994.36.Its Fo M was 2.7 times that of Ag mesh TE based on FTO substrate,which proved its better photoelectric performance.(4)A femtosecond laser was used to etch the mesh grooves on the PVP/PET substrate,and then the Ag mesh transparent electrodes were prepared on the flexible PET substrate.The photoelectric performance and environmental stability of the Ag mesh transparent electrode embedded in the flexible PET substrate were studied.And the thermal stability of the flexible transparent heating(FTH)was also studied.The results showed that transparent electrodes prepared have low sheet resistance of 0.86?/sq and high transmittance of 91.26%.At the same time,these TEs showed good environmental stability,maintaining good electrical conductivity in the air or deionized water without significant changes for 40 days.The fabricated representative flexible transparent heater(FTH)also presents stable heating performance,reaching a high temperature of 90 ~oC in 60 s under the driving of 1.0 DC voltage and finally stabilized at 98?.This performance is stable and consistent after 20 repetitions or under the condition of bending and twisting.Under a DC voltage of 1.0 V,FTH heated an ice cube with a volume of 600 mm~3,and the melting time was 140 s.