利用金属辅助化学腐蚀法在硅表面获得纳米绒面结构以提升多晶硅太阳电池效率

Nano-texturing of Silicon Surface via Metal-assisted Chemical Etching to Improve Efficiency of Polycrystalline Silicon Solar Cell

在硅片表面制备绒面结构能够有效降低太阳光在硅片表面的反射损失，是提高太阳能电池转换效率的一条重要途径。通过真空热蒸发法在多晶硅片上沉积纳米银颗粒，利用金属辅助化学腐蚀（MACE）法，制备了不同腐蚀时间下的纳米绒面结构，其中，腐蚀时间为60 s 的纳米绒面的平均反射率低至4.66%（300～1100 nm）。同时，对腐蚀时间为60 s的纳米绒面用KOH 溶液进行优化处理，将KOH 处理前后的多晶硅片采用常规电池工艺进行电池制备研究。对比发现，经过KOH 处理后的电池效率比未经KOH 处理的电池效率提高了0.43%。

Texturizing a silicon wafer is effective in driving down solar reflection loss on the wafer surface,thus providing an important way of improving solar cell conversion efficiency.Vacuum evaporation was used to deposit nano-silver particles on polycrystalline wafers,and nano-textured surfaces with various etching times were prepared and studied by means of metal-assisted chemical etching （MACE）technique.Specifically,the nano-textured surface with an etching time of 60 s produced a mean reflectivity as low as 4.66% （300-1100 nm）.The nano-textured sur-faces with 60 s etching time were further processed using KOH solution for optimization.Cells were fabricated by con-ventional fabricating process,using wafers with or without KOH processing respectively,and the comparative analy-ses confirmed a 0.43% higher efficiency of the cells with KOH processing compared to those without.