title: A highly photoconductive poly(vinylcarbazole)/2,4,7-trinitro-9-fluorenone Sol-Gel material that follows a classical charge-generation model.
abstract: Highly photoconductive properties are reported for organic-inorganic hybrid sol-gel thin film materials composed of a classical poly(vinylcarbazole)/2,4,7-trinitro-9-fluorenone (PVK/TNF) polymeric mixture, entrapped in a SiO(2) matrix, whose pores have been chemically modified by organic functional groups. The highest photosensitivity obtained, 3.4 x 10(-10) cm Omega(-1) W(-1) at E 22 V microm(-)1, at the optimum molar ratio between the active components, TNF, PVK, and SiO(2), is in the range of the highest values ever reported for any PVK/TNF-based classical photoconductive material. It is demonstrated that the PVK/TNF-based sol-gel films follow Onsager's classical charge-generation model. The analysis of the photocurrent efficiency (Phi) of PVK/TNF-based sol-gel films by such a model provides the primary quantum yield of thermalized pair formation and the initial thermalized pair distance, phi(0) = 0.12 and r(0) = 66.1 Angstrom, respectively, for the optimized sample. As a result of Onsager's analysis, a notorious improvement of the photocurrent generation process was achieved for low TNF concentrations.
authors.affiliation: Instituto Nacional de Técnica Aeroespacial-INTA, Laboratorio de Instrumentación Espacial-LINES, Torrejón de Ardoz, 28850 Madrid, Spain. ramoszg@inta.es
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Ramos
authors.forename: Tomas
authors.initials: T
authors.lastname: Belenguer
authors.forename: David
authors.initials: D
authors.lastname: Levy