Size-controlled nc-Si:H/a-SiC:H quantum dots superlattice and its application to hydrogenated amorphous silicon solar cells

Abstract

Boron doped nc-Si:H/a-SiC:H quantum dot superlattice (QDSL) has a great potential to improve thin film silicon solar cells performance for high conductivity, wide band gap and anti-reflection effect. In this study p-type nc-Si:H/a-SiC:H QDSL has been fabricated by in situ grown method without subsequent annealing treatment. High resolution transmission electron microscopy and PL peak energy shift indicate that this method provides the possibility to precisely control the size of silicon quantum dots and the passivation at well/barrier interface. By optimizing structural characteristics and interface passivation, high perpendicular conductivity and strong anti-reflection effect was simultaneously obtained in QDSL films. An initial efficiency of 10.5% was achieved for n-i-p type hydrogenated amorphous silicon solar cell, which may guide further efforts arising the structure engineering of nc-Si:H/a-SiC:H QDSL for high efficient solar cells.