Recent progress in Si-PEDOT:PSS inorganic–organic hybrid solar cells

In this topical review, the development of Si-PEDOT:PSS inorganic–organic hybrid solar cells is briefly summarized. After an introduction to the typical device structure and relevant operating mechanism, special focus is placed upon ways to enhance solar cell efficiency. The various approaches for improving cell performance have been categorized into three sub-topics: (1) micro-/nano-structuring of the Si surface for effective light manipulation and trapping, (2) interface engineering for efficient charge carrier separation and extraction, with special focus on 'dopant-free selective contact' approaches, and (3) electrical optimization of PEDOT:PSS via 'secondary doping', including their molecular mechanism and analytical characterization methods. Finally, remaining hurdles to be overcome for hybrid solar cells are discussed, including novel applications of unique inorganic–organic heterojunction structures such as photodetectors and photoanodes in photoelectrochemical cells. Moreover, non-planar, deformable forms of Si-PEDOT:PSS hybrid cells are introduced, which may be very useful devices for various portable, off-grid applications. (topical review)