Dye Sensitization of Photoconductivity of Poly-N-Vinylcarbazole. I. Quantum Yield

Abstract

The photocurrent of the dye-sensitized poly-N-vinylcarbazole (PNVC) film was measured. The dyes were used carbonium salts, benzopyrylium salts and crystal violet. These dyes were found to enhance the photocarriers in the film both at the first excitation band of PNVC and at the excitation band of the dyes. Since photocarriers were observed to be holes, it is concluded that the electron transfer occurs from PNVC to dyes with the absorption of photons and that the quantum yield of photocarriers is related to the rate of this electron transfer. The quantum yield was deduced from the combination of the photocurrent and the decay rate of the surface charge and was found to be more than 10^-1 for the excitation of PNVC and 10^-2∼10^-1 for the dye-excitation.