基于倒金字塔减反射结构的多晶黑硅及其高效太阳电池

Investigation on Multi-crystalline Black Silicon and High Efficiency Solar Cell Based on Inverted Pyramid Antireflective Structure

采用酸体系的纳米重构(Nano structure rebuilding,NSR)溶液对黑硅纳米结构进行重构,得到不同尺寸的倒金字塔减反射微结构,实现了低成本纳米减反射微结构多晶黑硅(Multicrystalline-black silicon,mc-bSi)太阳电池的量产。先用Ag金属催化腐蚀(Metal assisted chemical etching,MACE)对砂浆切割(Multi wire slurry sawn,MWSS)多晶硅片(Multicrystalline silicon,mc-Si)进行了研究,发现倒金字塔结构的面夹角均为54.7°,且500nm尺寸大小的倒金字塔结构黑硅太阳电池的转换效率达到了18.62%,电池的表面反射率降低至3.29%。研究了Ag/Cu双原子催化腐蚀法对金刚线切割(Diamond wire sawn,DWS)多晶硅片的制绒效果,发现多晶硅片表面金刚线切割痕几乎消失不见,采用倒金字塔尺寸为600nm的DWS片样品制备出了性能最佳的太阳电池,其开路电压Voc为640mV,短路电流密度Jsc为37.35A/cm2,填充因子FF为79.91%,最高效率为19.10%,高于同结构的MWSS多晶黑硅太阳电池。

Different scales of the inverted pyramid structure are obtained by the acidic nano structure re- building （NSR） process, which realizes the mass prodution of high efficiency nanostructured multicrys- talline-black silicon （mc-bSi） solar cells with low cost. Firstly, the multi wire slurry sawn （MWSS） of multi crystalline silicon（mc-Si） is investigated through silver metal assisted chemical etching（MACE）. Results show that the dihedral angels of inverted pyramid maintain at 54. 7~. The inverted pyramid structured mc-bSi solar cell shows the best efficiency of 18.62% , with 500 nm inverted pyramid struc- ture by 400 s NSR treatment at 50℃, and the surface reflectance is 3.29%. Furthermore, the paper studies the texture property obtained by Ag/Cu MACE method and NSR treatment on diamond wire sawn （DWS） mc-Si. The research results show that the saw marks on DWS mc-Si surface are nearly dis- appeared. We obtain the optimal DWS mc-Si solar cell with the same size of 600 nm invert pyramid sam-ple, with Voc, Joc and FF at 640 mV, 37.35 A/cmz and 79.91%, respectively, and the maximum con- version efficiency is 19.10% which is higher than that of MWSS mc-bSi solar cell.