High photosensitivity with enhanced photoelectrical contribution in hybrid nanocomposite flexible UV photodetector

To devise a reliable strategy to develop an ultraviolet (UV) sensitive hybrid photodetector, plasma process is utilized as a single step method for production of large area nanocomposite films based on plasma polymerized aniline-titanium dioxide (PPani-TiO2). The synthesis of PPani-TiO2 nanocomposite films are made using reactive magnetron sputtering in combination with plasma polymerization. The deposited PPani-TiO2 nanocomposite films are characterized and discussed in terms of structural, optical and electrochemical properties. A hybrid flexible nanostructured UV photodetector is constructed from PPani-TiO2 nanocomposite and its optoelectronic properties are evaluated which exhibits a greatly enhanced photosensitivity resulting in high photoconductive gain (G = 4.56 x 10(4)) and high responsivity (R = 9.36 x 10(3) AW(-1)) under UV illumination of 254 nm. The flexible devices are successfully operated under bending up to 170 degrees (bending radius, R = 8 mm) and showed a good folding strength and stability. The proposed plasma based method provides a green technology where the self-assembly of molecules, that is, the spontaneous association of atomic or molecular building blocks under plasma environment, emerge as a successful strategy to form well-defined structural and morphological units of nanometer dimensions. (C) 2014 Elsevier B.V. All rights reserved.