Extrinsic Carrier Photogeneratien in Poly-N-vinylcarbazole (III)

—Sensitization of Poly-N-vinylcarbazole Using Intramolecular Charge Transfer Complexes—

Abstract

Photosensitization of poly-N-vinylcarbazole (PVK) was investigated using three different structured intramolecular charge transfer (CT) complexes consisting of carbazole donor chromophore and tricyanovinyl accepting group as a sensitizer. These compounds show considerably high sensitization in their respective intramolecular CT absorption bands. From the analyses of the induced photocurrents in pulse photoconduction measurements, the initial separation and quantum yield of ion pairs were estimated based on the Onsager model. Compared with intermolecular CT complex sensitization in PVK-TNF (2, 4, 7-trinitrofluorenone) and PVK-TCNE (tetracyanoethylene) systems, the higher quantum yield but smaller initial separation (r₀=22 Å) of ion pairs was obtained independently of the structure in the present intramolecular CT complexes.