Antireflection properties and solar cell application of silicon nanoscructures
硅基纳米结构的减反特性及其在太阳能电池中的应用

Silicon nanowire arrays (SiNWAs) are fabricated on polished and pyramids textured Si using an aqueous chemical etching method. The silicon nanowires itself or hybrid structure of nanowires and pyramids both show strong anti-reflectance abilities in the wavelength region of 300 ~ 1000nm, and reflectance of 2.53% and less than 8% are achieved, respectively. A 12.45% SiNWAs-textured solar cell (SC) with short circuit current of 34.82mA/cm2 (Isc) and open circuit voltage (Uoc) of 594mv was fabricated on 125125 mm2 Si using conventional process including metal grid printing. It is revealed that passivation is essential for hybrid structure textured SCs, and the Uoc can be enlarged by 28.6% from 420V to 560mv after passivation layer is deposited. The loss mechanism of SiNWAs SC was investigated in detail by systematical comparison of the basic parameters and external quantum efficiency (EQE) of samples with different fabrication process. It is proved that surface passivation and fabrication of metal grid is critical for high efficiency SiNWAs SC and the performance of SiNWAs SC could be improved when fabricated on a substrate with initial PN junction.