Research On Preparation And Performance Of Organic Carriers For Crystalline Silicon Solar Electrode Paste

Since the first industrial revolution,fossil energy has become the main energy source for human daily life.In recent decades,with the gradual depletion of traditional energy sources,solar energy has begun to serve as an effective alternative to traditional fossil energy sources.The crystalline silicon solar cell is currently the photovoltaic cell with the widest application range and the most mature preparation process.As an important raw material of solar cells,conductive paste affects the photoelectric conversion rate and the cost of solar cells.The output of photovoltaic cells in my country is large while some electrode materials such as conductive paste still rely on imports.Therefore,conductive paste preparation technology has been the focus of the national photovoltaic industry in recent years.The conductive paste for crystalline silicon solar cells is divided into front-side silver paste,back-side silver paste and back-side aluminum paste according to its using and printing position.All three types of pastes are composed with conductive phase,organic vehicle and glass powder.The organic carrier has a great influence on the electrical performance of the battery.In this paper,by studying the viscosity,volatility and thixotropy of the organic carrier,adjusting the ratio of the carrier components,the organic carrier is prepared in line with the solar cell paste.First of all,the carrier solvent with the best volatility is obtained through the volatilization test of different solvents in this paper.Then the solvent system is used to observe the changes of carrier viscosity and thixotropy index by controlling the content of EC and thixotropic agent,and finally obtained The aluminum paste carrier solvent is a mixed solvent composed of terpineol,butyl carbitol acetate,acetyl tributyl citrate and alcohol ester twelve.The content of the mixed solvent in the carrier is 95.2wt%,and the content of thickener 4wt%,thixotropic agent content 0.8wt%,carrier viscosity is 7933.33 m Pa·s,thixotropy index reaches 2.06,the carrier can evaporate smoothly at 120-330℃.The secound,Then combine the research of silver paste to optimize the solvent composition in the aluminum paste carrier,choose propylene glycol methyl ether acetate instead of terpineol,propylene glycol methyl ether acetate was selected instead of terpineol,and dibutyl phthalate was substituted for acetyl tributyl citrate,which was used as the organic silver paste.In the solvent system for the carrier,the ratio of thixotropic agent and thickener and the influence of different additives on the viscosity of the carrier are also studied to further increase the viscosity and thixotropy of the carrier to meet the viscosity requirements of positive silver.The final prepared positive silver carrier has an organic solvent content of 87.57%,a thickener content of 6wt%,and a thixotropic agent content of 3.5wt%.In addition,5.5wt% of PB400 is added as an organic additive to improve the thixotropy of the carrier.The prepared carrier has a viscosity of 67150 m Pa.s and a thixotropic index of 8.49.Has excellent thixotropy.The organic solvent content of the back silver carrier is93.5%,the thickener content is 1.5wt%,and the thickener content is 5wt%.The viscosity of the carrier is 26156 m Pa·s,and the thixotropy index is 2.576.Both of these two silver paste carriers can volatilize smoothly between 120°C and400°C.On the basis of previous research on carriers,three types of carriers,conductive powder and glass powder are made into conductive paste.The resulting aluminum paste uses spherical aluminum powder as the conductive phase.The solid content of the paste is 76.06% and the viscosity is 46Pa· s,the thixotropic index is 4.47,and the paste fineness is 11μm.The aluminum powder is closely arranged in the paste.The back silver paste uses flake silver powder as the conductive phase.The solid content of the paste is 44.3%,the viscosity is74 Pa·s,and the fineness of the paste is 26μm.The back silver organic carrier can make the paste denser under the condition of low silver content.The conductive network.The positive silver paste uses spherical silver powder as the conductive phase,with a solid content of 91.23%,a viscosity of 231 Pa·s,a thixotropy index of 6.24,and a paste fineness of 24 μm.The silver paste made from the positive silver organic carrier has high contact Denaturation and suitable viscosity.The three organic vehicles developed in this paper have been prepared into conductive pastes and all show excellent performance.