Crystalline silicon / organic thin film heterojunction based solar cells have been realized using spin-coating deposition.
Devices with different organic films, all based on PEDOT:PSS, which in some cases have been mixed with double-walled
or multi-walled carbon nanotubes, have been compared. Highest conversion efficiencies have been obtained
either with a highly conductive PEDOT:PSS emitter withut nanotubes or with a nanocomposite emitter consisting of low
conductive PEDOT:PSS emitter mixed with multi-walled carbon nanotubes. Using the nanocomposite emitter, rather
high values for the solar cell shunt resistances have been obtained without any etching procedure in order to improve the
lateral current confinement. A comparison with a Schottky diode, realized as reference device by the evaporation of the
top metal contact directly on top of the crystalline silicon substrate, showed that the heterodiode characteristics was not
dominated by leakage current paths and short circuits through the organic layer.