Achieving a Record Fill Factor for Silicon-Organic Hybrid Heterojunction Solar Cells by Using a Full-Area Metal Polymer Nanocomposite Top Electrode

Carrier collection in conventional n-type Si (n-Si)/organic hybrid heterojunction solar cells (HHSCs) is mainly limited by the nonoptimized top grid-electrode and inadequate work function (WF) of the PH1000-type poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). Here, a novel modified metal polymer nanocomposite top electrode (M-MPNTE) is designed to achieve a full-area carrier collection in n-Si/PEDOT:PSS HHSCs. The carrier collection in both lateral and vertical directions is significantly improved by the introduction of an ultrathin Au/MoOx modified layer between 6 nm ultrathin Ag film and AI4083-type PEDOT:PSS layer. In addition, the carrier separation is boosted by the enhanced built-in potential owing to a high WF of M-MPNTE, which also suppresses the carrier recombination at the surface of n-Si. Due to these collaborative improvements, a record fill factor of 80.21% is obtained, which is even comparable to the best value of the traditional Si-based solar cells. With the addition of a MoOx antireflective coating layer on top of M-MPNTE, the short-circuit current density and open-circuit voltage are finally increased to 23.13 mA cm(-2) and 621.07 mV, respectively, yielding a power conversion efficiency of 10.82%. The finding suggests a novel strategy for the development of highly efficient HHSCs with ideal carrier transport mechanism.