High-performance Si/organic hybrid solar cells using a novel cone-shaped Si nanoholes structures and back surface passivation layer

Abstract Nanostructured silicon (Si) can provide improved light trapping capacity in Si/organic hybrid solar cells (HSCs) due to its low light reflectance compared with planar Si. However, the poor contact of nanostructured Si/organic interface and serious recombination on the uncovered Si surface can result in an inferior open-circuit voltage ( V OC ) and fill factor ( FF ) for HSCs. Here, we have designed and fabricated a novel cone-shaped Si nanoholes (SiNHs) structures to form a superior interface contact between SiNHs and organic layer by using an advanced metal assisted chemical etching method. In addition, a Cs 2 CO 3 layer was also introduced on the Si back surface to reduce the contact resistance as well as to suppress the surface recombination for the HSCs. With such improvements, a power conversion efficiency (PCE) up to 13.5% was achieved for Si/organic hybrid solar cell with the back passivation layer. This work provided a new strategy to improve the junction quality and performance of nanostructured Si/PEDOT:PSS HSCs.