Improving performance of organic-silicon heterojunction solar cells based on textured surface via acid processing.

Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS) is widely applied in organic-photoelectronic devices due to its excellent transparency and conductivity. However, when it is used to the organic-silicon heterojunction solar cells with traditional pyramid texturing surface, the device is limited by the contact between the PEDOT:PSS and silicon wafer at the bottom of the pyramids. We optimized the structure of the bottom of the pyramids via acid isotropic etching (AIE) method with mixed acid solution to ensure the silicon wafer is fully covered by the PEDOT:PSS. In addition, hydrogenated amorphous silicon thin films were deposited with PEVCD method as the passivation and back surface field (BSF) layer to decrease the rear surface recombination rate, thus increasing the long wavelength response. Finally, a power conversion efficiency of 13.78% was achieved after depositing MoO3 on the front of the device as the antireflection layer.