Reverse Switching Phenomena in Hybrid Organic–Inorganic Thin Film Composite Material

• Published in: Journal of physical chemistry. C Vol. 117; no. 1; pp. 124 - 130
• Main Authors: Mohanta, Kallol, Rivas, Jose, Pai, Ranjith Krishna
• Format: Journal Article
• Language: English
• Published: Columbus, OH American Chemical Society 10.01.2013
• Subjects: Applied sciences; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport in multilayers, nanoscale materials and structures; Electronics; Exact sciences and technology; Materials science; Molecular electronics, nanoelectronics; Nanocrystalline materials; Nanoscale materials and structures: fabrication and characterization; Physics; Quantum dots; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Ultrathin films; Composite film; Electronic properties; Electrical conductivity; Electrical properties; Quantum dots; Core shell structure; Hybrid material; Fluorescence; Switching; Thin films; Scanning tunneling microscopy; Energy gap; Composite materials; Organic-inorganic hybrid materials; Functionalization; II-VI semiconductors; Thin film devices; Electric field effects; Detectors; Sensors; Nanostructured materials
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/jp309750p

A systematic approach was followed to develop a new hybrid organic–inorganic composite material with intriguing electrical and fluorescence properties into one ultrathin film system. Providing facile and cost-effective synthesis, this method utilizes a double decomposition reaction to introduce electric and fluorescence as an intrinsic property into one ultrathin film system, through dihydrolipoic acid-coated core/shell CdSe/ZnS quantum dots. Scanning tunneling microscope was used to asses, at the microstructured level, electrical properties of the composite material. Thin film composite devices exhibit higher conductivity with the application of a lower electrical field and inversely show lower conductivity when applying higher electrical bias point. The prospect of this feature solely lies in band gap engineering inherent to the device structure and geometric properties. The merits of such a device, paired with the ease of chemical functionalization provided by the water-soluble quantum dots, make the obtained hybrid organic–inorganic thin film composite material a viable candidate to be used as sensors, optolectronic devices, as well as pathogenic detectors.