Research On Preparation And Application Of Functional Inks For Inkjet Printing

Inkjet printing technology,based on computer control technology,is an advanced printing technology,which integrates precision mechanical technology,software information technology and fine chemical technology.Inkjet printing technology has the advantages of high printing precision,fast deposition speed,diversified printing patterns,simple printing process and environmental friendliness.It is one of the most promising functional material manufacturing technologies for the time being.The preparation of inkjet ink and the regulation of inkjet printing process parameters are the core parts of the application of inkjet printing technology.In this paper,Co-based blue glass ink,Ag ink and perovskite ink are taken as the main line,and the relationship between the preparation and composition of different inkjet inks and the inkjet suitability of inks are studied respectively.The difference in the control mechanism between the printing process parameters and the device performance is intended to provide theoretical basis and experience guidance for inkjet printing technology being applied in new functional materials manufacturing.The main research contents and conclusions of this thesis are as follows:?1?The composite Co-based blue pigments Zn_xMg_yCo_0.5Al₂O₄?x+y=0.5?with partly Co²⁺being co-substituted by Zn²⁺/Mg²⁺were successfully prepared by Pechini chemical synthesis method,revealing the relationship between relative content of Zn²⁺/Mg²⁺and the properties of Co-based blue pigment.The results show that Zn²⁺/Mg²⁺co-substituted Co²⁺in CoAl₂O₄ spinel structure to form a replacement solid-solution structure.Compared with Mg²⁺,Zn²⁺can more effectively inhibit the formation of Co₃O₄ impurity crystal phase and promote the formation of spinel structure from free Al₂O₃.When the molar ratio of Zn²⁺/Mg²⁺is 0.3:0.2,the composite Co-based blue pigment Zn_0.3Mg_0.2Co_0.5Al₂O₄ has the highest crystallinity,excellent optical properties,and the blue color fullness and brightness are the highest.?2?Using ultrasonic-assisted magnetic stirring method,the Co-based blue glass ink that meets the requirements of inkjet printing technology was successfully prepared.The experiments found that the optimum mass ratio of Co-based blue pigment to low-melting-point glass adhesive is 91:9,the best ball-milling process is a speed of⁵00 rpm,and the ball-milling time is¹6 h.Co-based blue glass ink has a solid content of 35 wt%,a viscosity of 18.21 mPa·s,a surface tension of 29.18mN·m^-1,and a pH of 7.5,which is suitable for drop-on-demand inkjet printing systems.The Co-based blue glass ink layer was annealed at 650°C for 10 min to obtain a Co-based blue glaze layer.The analysis of Co-based blue glaze sample indicates that the Co-based blue pigment was uniformly dispersed in the low-melting-point glass matrix,and there are not obvious defects such as pores,cracking and chromatic aberration existing on the surface or in the interior of the glaze layer.?3?Using high-throughput screening method,the difference of PVP,F-127,SDS and tri-sodium citrate in particle size controlling effect during the chemical reduction of nano-sized Ag particles was intensively studied.PVP stabilizer has the strongest effect on the size controlling of the Ag nano-sized particles,which is because of the combination of the steric hindrance of the long chain and the electrostatic steric hindrance at the end of the molecular chain.The Ag ink has a solid content of 5 wt%,a viscosity of 12.32 mPa·s,a surface tension of 27.11 mN·m^-1 and a pH of 9.0.The Ag ink was subjected for inkjet printing test,and results depict that when the number of inkjet printing runs was 50,the obtained Ag wire was the most uniform and dense,and the conductivity was the best with a minimum sheet resistance of⁰.86?/?.?4?The Ag-mesh electrode,for ITO replacement,was fabricated by inkjet printing technology,which facilitates to realize the ITO-free perovskite solar cells.The results show that polyvinyl acetate can effectively improve the film-forming properties of Ag ink on glass surface when acting as a surface modification material.The optimized inkjet printing process parameters are 32?m drop spacing,9 nozzles,and the annealing temperature and time are 220°C and 20 min,respectively.The thickness of the obtained Ag-mesh electrode was³00 nm,and the sheet resistance was⁵6 m?/?.Through the anti-solvent method and the electron transport layer optimization experiment,the perovskite film formation quality and device performance were effectively improved,and the photoelectric conversion efficiency of the MAPbI₃ and Cs_0.02MA_0.6FA_0.38PbI_2.975Br_0.025 perovskite solar cells based on the Ag-mesh electrode were finally achieved to 1.48%and 3.7%,respectively.?5?The two-dimensional perovskite BA₂MA₃Pb₄I₁₃ activation layer was successfully prepared by inkjet printing technology for the first time.The experimental results show that the evaporation rate of solvent in the BA₂MA₃Pb₄I₁₃precursor ink is the most important factor affecting the two-dimensional perovskite film crystallization,thickness and morphology.The optimized printing process parameters are as follows:the drop spacing is 40?m,the number of printed layers is 1and the substrate deposition temperature is 30°C.Further optimization of the concentration of BA₂MA₃Pb₄I₁₃ precursor ink shows that the inkjet printing BA₂MA₃Pb₄I₁₃ two-dimensional perovskite solar cell has the best photoelectric conversion performance of 8.77%PCE when the concentration is 0.8 mol/L.