【摘要】 介绍了一种用铜作催化剂,辅助单步湿法刻蚀多晶硅片的工艺。该方法具有成本低廉和操作简易的特点。系统研究了反应物浓度和温度对刻蚀速率以及刻蚀后硅片表面形貌的影响,并据此通过调节反应物浓度cHF∶cH2O2=6 mol/L∶2 mol/L,cCu(NO3)2=0.08 mol/L以及反应温度至60℃,得出了最佳的刻蚀参数配比。制备出的多晶硅纳米结构表面,平均反射率在宽波段内降低到5%,陷光减反作用明显。可引用空穴注入模型解释不同反应物浓度下硅片表面形貌的形成机理。通过公式拟合与实验结果的对比,提出了反应活化能以及铜与硅片的接触面积是影响刻蚀过程的内在因素。更多还原

【Abstract】 The research on the metal assisted chemical etching for the nanostructure fabricated on Si wafers for solar cells is carried out greatly in recent years.For the purpose of low cost and simplification,a novel one-step assisted chemical etching method with Cu as the catalyst was introduced to etch the polycrystalline silicon.The effects of the reactant concentration and reaction temperature on the etching rate and surface morphology of the Si wafers after etching were systematically studied.For low reflectivity,an optimal etching condition of cHF∶cH2O2=6 mol/L∶ 2 mol/L,cCu(NO3)2=0.08 mol/L and the reaction temperature of 60 ℃ was obtained.The 5% average surface reflectivity of the prepared polycrystalline silicon nano structure was achieved for the wide band,and the significant anti-reflection effect for light trapping was obtained.The formation mechanism of the surface morphology of the Si wafers under different reactant concentrations can be explained with the hole injection model.Through the comparison of the fitting formula and experimental results,it is pointed out that the reaction activation energy and the contact area between copper and silicon are the main internal factors in the etching process.更多还原