Chemical mist deposition of graphene oxide and PEDOT:PSS films for crystalline Si/organic heterojunction solar cells

The chemical mist deposition of graphene oxide (GO) and poly(3,4-ethylenedioxythiophene):poly(stylenesulfonate) (PEDOT:PSS) were investigated on the crystalline silicon (c-Si) substrate for the n-type c-Si/organic heterojunction solar cells. The uniform coating of GO flake with an average size of 1-5 μm was obtained on the hydrophobic c-Si wafer using deionized water as a solvent. The GO layer thickness could be controlled from a monolayer to a few tens of nanometres by vary- ing mist deposition time. The c-Si/GO/ PEDOT:PSS heterojunction solar cells shows the efficiency improved from 8.75 to 9.27% with insertion of GO flakes a the PEDOT:PSS and c-Si interface owing to the enhanced suppression of electron recombination and/or promotion of hole current at the anode. Furthermore, the CMD was also applied to coat conductive PEDOT:PSS films on the textured c-Si. The η of 7.75% was obtained with a short-circuit current of 34.22 mA/cm2, a open-circuit voltage of 0.46 V, and a fill factor of 0.48. These findings imply that CMD is a promising method for the uniform deposition of both nanomaterials (GO) and conjugated polymer for the c-Si/ organic heterojunction solar cells (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)