Photosensitization and photocurrent switching effects in wide band gap semiconductors: CuI and TiO2 functionalized with iron and nickel complexes: from semiconductors to logic devices

摘要

Materials obtained by immobilization of nickel and iron complexes on the surface of n-type titanium dioxide and p-type copper iodide have interesting photoelectrochemical properties. Fe(NA)Cl-2@ TiO2, Fe(NA) Cl-2@ CuI, Ni-rutin@CuI and Ni-rutin@TiO2 exhibit pronounced photosensitization towards visible light and photoelectrodes prepared from these materials generate photocurrents over a broad light wavelength window. The polarity of the generated photocurrents varies with change of the applied potential. Photocurrent switching phenomena can be described in terms of photoinduced charges transfer involving semiconductor and excited metal complex. Various types of interaction between semiconductor and adsorbed complex reflected in different mechanism of photosensitization. The studied materials has been characterized using various spectroscopic, crystallographic and electrochemical methods. Based on the photochemical measurements and diffuse reflectance spectroscopy the mechanism of photosensitization as well as mechanism of photocurrent generation in various conditions have been suggested. Due to interesting photoelectrochemical properties, studied materials are promising for optoelectronic logic devices such as demultiplexer. Studied materials are particularly attractive due to high stability and photostability.