(中南大學(xué) 材料科學(xué)與工程學(xué)院，長沙 410083)
摘 要: 采用液相化學(xué)還原法，以十二烷基三甲基溴化銨(CTAB)作分散劑，抗壞血酸作還原劑還原硝酸銀溶液制備太陽能電池用微細(xì)銀粉，通過調(diào)節(jié)分散劑用量、pH值、Ag+濃度以及反應(yīng)介質(zhì)類型可以對(duì)銀粉的粒徑和分散性進(jìn)行控制，并用XRD和SEM對(duì)所得到的銀粉進(jìn)行表征。結(jié)果表明：十二烷基三甲基溴化銨與銀離子的結(jié)合以及自身長碳鏈的位阻效應(yīng)能夠在微細(xì)銀粉的制備過程中起到很好的分散作用。通過工藝優(yōu)化最終可得到平均粒徑為0.7 μm、振實(shí)密度為4.0 g/mL、分散性良好的球形或類球形銀粉。以此銀粉配制的銀漿制成的多晶硅太陽能電池正面電極致密度高，光電轉(zhuǎn)換效率可達(dá)17.8%。
關(guān)鍵字: 太陽電池；高分散；微細(xì)銀粉；化學(xué)還原
（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
