Study On Effect Of Na Additives On Properties Of Mo-Na Alloy Targets

In the manufacturing of thin-film solar cells,the multi-component semiconductor CIGS?Cu?In,Ga?Se2?is commonly applied as basic material.In solar cells,Mo-Na film layer is used as the back electrode,which can effectively improve the photoelectric conversion efficiency.Mo-Na thin films are usually prepared with Mo-Na alloy targets by DC magnetron sputtering.The preparation of high quality thin films requires the premise of high quality targets.The high quality target material of Mo-Na alloy requires uniform and fine grain,high densification,ensuring Na content and no other impurities,etc.However,it is very difficult to meet above conditions.At present,the research and production of Mo-Na alloy target material started very late in China,and no mature Mo-Na alloy target material is applied effectively.Therefore,the preparation of high quality Mo-Na alloy targets has attracted much attention in this field.In this study,high purity Mo powder was used as the matrix material,and different sodium additives?Na₂MoO₄·2H₂O,Na2CO3 and NaOH,respectively?were applied to prepare Mo-Na alloy.The influence of sodium additives on the preparation process was systematically studied,and corresponding samples of Mo-Na alloy target material were prepared and processed according to the national standards of Mo-Ti alloy target production.The main results are as follows:?1?The effects of Na₂MoO₄·2H₂,Na2CO3 and NaOH sodium additives on the properties of target materials of Mo-Na alloy were investigated through the process of "pressure forming + vacuum sintering".?2?When the additives Na₂MoO₄·2H₂,Na2CO3 and NaOH were doped respectively to prepare Mo-Na alloy,Mo-Na alloy materials with good comprehensive properties such as density,hardness and internal microstructure were obtained.Through the further determination and analysis of the chemical composition,properties and microstructure comparison of Mo-Na alloy samples prepared with different sodium additives.NaOH was selected as an excellent target material for Mo-Na alloy preparation,followed by Mo-Na alloy prepared with Na₂MoO₄·2H₂ doping.The Mo-Na alloy prepared by doping Na2CO3 was not satisfied.?3?In this study,NaOH additive was used to prepare the target material of Mo-Na alloy.The density problem of the sample was solved by adjusting the pressure of hydraulic press.The raw mixed Mo-Na powder was pressed at 1200 MPa and the density was high and had no cracks after vacuum sintering.After machining,the surface finish of the alloy target sample is increased,and the internal grains of the alloy sample are uniform and fine,the structure is dense,and there is no segregation and accumulation of doped elements.