Hybrid organic-inorganic semiconductor structures and sensors based thereon

Abstract

A hybrid organic-inorganic semiconductor device is provided as a sensor for chemicals and light, said device being composed of: (i) at least one layer of a conducting semiconductor such as doped n-GaAs or n-(Al,Ga)As; (ii) at least one insulating layer such as of an undoped semiconductor; e.g. GaAs or (Al,Ga)As; (iii) a thin layer of multifunctional organic sensing molecules directly chemisorbed on one of its surfaces, said multifunctional organic sensing molecules having at least one functional group that binds to said surface and at least one another functional group that serves as a sensor; and (iv) two conducting pads on the top layer making electrical contact with the electrically conducting layer, so that the electrical current can flow between them at a finite distance from the surface of the device. The surface-binding functional group of the multifunctional organic sensing molecule may be one or more aliphatic or aromatic carboxyl, thiol, sulfide, hydroxamic acid or trichlorosilane groups. The functional group that serves as a sensor may be a group suitable for binding and detection of metal ions such as Cu , Fe and Ru such as radicals derived from hydroxamic acids, bipyridyl, imidazol and hydroxyquinoline, or a group that is an efficient light absorber at a given wavelength and is suitable for detection of light such as radicals derived from aliphatic or aromatic hydroxamates, substituted aromatic groups such as cyanobenzoyl and methoxybenzoyl, bipyridyl, hydroxyquinoline, or imidazolyl groups to which a metal porphyrin or a metal phtalocyanin residue is attached.