PEDOT:PSS/SiNWs Hybrid Solar Cells With an Effective Nanocrystalline Silicon Back Surface Field Layer by Low Temperature Catalytic Diffusion

PEDOT:PSS/Silicon nano-wires (SiNWs) hybrid solar cells have significant potential to reduce costs due to use of simple spin coating process. The front surface of the silicon substrates is textured by using metal-assisted chemical etching (MACE) to improve light harvesting and to enlarge contact area between the silicon substrate and the polymer. An ultra-thin n-type silicon film with high conductivity, served as passivation and back surface field (BSF) layer at the same time, is formed at the back side of the silicon substrates by using low temperature catalytic diffusion carried out in a hot wire chemical vapor deposition chamber. The influences of the low temperature catalytic diffusion process on the conductivity and micro-structure of the ultra-thin silicon film are presented and discussed. The role of the ultra-thin silicon film in the hybrid solar cells is analyzed based on an amorphous/nano-crystalline silicon double-layer model. A power conversion efficiency (PCE) up to 15% is achieved for PEDOT:PSS/SiNWs hybrid solar cell.