Preparation of nanocomposites of polyaniline and inorganic semiconductors

Nanocomposites of polyaniline (PANI) and the semiconducting metal sulfides CdS and Cu2S were prepared from the respective metal trifluoromethanesulfonates co-dissolved in N-methylpyrrolidone. Metal sulfide particles with typical diameters of 1-2 nm formed in situ upon addition of Li2S; the nanocomposites were subsequently isolated by co-precipitation. UV/VIS absorption spectra suggest that the PANI-CdS nanocomposites are stable in the air, while PANI was found to degrade in the presence of Cu2S. Appreciable photovoltaic effects were measured on multilayer devices based on Al/nanocomposite/ Cd1-xZnxO and Al/nanocomposite/C-60/Cd1-xZnxO. In the absence of the C-60 layer, both open circuit photovoltage (U-oc) and short circuit photocurrent (Isc) were found to increase substantially with increasing CdS content, while in the presence of a C-60 layer, more complex behavior was observed.