(中南大学 材料科学与工程学院，长沙 410083)
摘 要: 采用液相化学还原法，以十二烷基三甲基溴化铵(CTAB)作分散剂，抗坏血酸作还原剂还原硝酸银溶液制备太阳能电池用微细银粉，通过调节分散剂用量、pH值、Ag+浓度以及反应介质类型可以对银粉的粒径和分散性进行控制，并用XRD和SEM对所得到的银粉进行表征。结果表明：十二烷基三甲基溴化铵与银离子的结合以及自身长碳链的位阻效应能够在微细银粉的制备过程中起到很好的分散作用。通过工艺优化最终可得到平均粒径为0.7 μm、振实密度为4.0 g/mL、分散性良好的球形或类球形银粉。以此银粉配制的银浆制成的多晶硅太阳能电池正面电极致密度高，光电转换效率可达17.8%。
关键字: 太阳电池；高分散；微细银粉；化学还原
（School of Material Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The highly dispersive ultra-fine spherical silver powder for solar cells was prepared by liquid phase reduction method using cetyltrimethyl ammonium bromide (CTAB) as the dispersant, ascorbic acid as the reducing agent reducing AgNO3 solution. The particle size and dispersion can be regulated by adjusting the amount of CTAB, pH, Ag+ concentration as well as reaction medium. X-ray diffractometry (XRD) and scanning electron microscopy (SEM) were employed to characterize the prepared silver particles. The results show that the combination between CTAB and Ag+ as well as the excellent steric hindrance effect are good for the dispersion of silver powder during the reaction. Silver powder with average particle size of 0.7 μm, tap density of 4.0 g/mL can be obtained by the process optimal. The density of the front electrode of polycrystalline solar cells made by silver pastes prepared silver powder is high, and the photoelectric transformation efficiency reaches 17.6%.
Key words: solar cell; high dispersion; ultra-fine silver powder; chemical reduction
