Plasma process for development of a bulk heterojunction optoelectronic device: A highly sensitive UV detector

Deposition of composite thin film of polyaniline/TiO2 (PAni/TiO2) has been carried out by a combined process of magnetron sputtering and plasma polymerization at a pressure of 5×10−2Torr using titanium as target material for sputtering, aniline as monomer, oxygen as reactive gas and argon as carrier gas/ion source for sputtering. The deposition has been achieved using dc discharge power of 35W for sputtering and radio frequency (rf) power of 8–12W at substrate bias values in the ranges of −80 to −100V for polymerization. The ultraviolet (UV) photo-stability of the composite film has been studied by exposing the film deposited on silicon substrate for different reaction times up to 1h under UV radiation at wave length range of 280–400nm with intensity 0.4mW/cm2. An organic/inorganic nanocomposite film based photovoltaic device has been developed. The device has an aluminum/composite/indium tin oxide sandwiched structure that shows strong photoresponse in ultraviolet region and hence the device has potential for application as an UV detector. [Display omitted] ► Polyaniline/TiO2 (PAni/TiO2) film has been deposited by a combined process of magnetron sputtering and plasma polymerization. ► An organic/inorganic nanocomposite film based photovoltaic device is developed. ► The device has an aluminum/composite/indium tin oxide sandwiched structure. ► The device shows strong photo-response in ultraviolet region, so it has potential for application as an UV detector. Deposition of composite thin film of polyaniline/TiO2 (PAni/TiO2) has been carried out by a combined process of magnetron sputtering and plasma polymerization at a pressure of 5×10−2Torr using titanium as a target material for sputtering, aniline as monomer, oxygen as reactive gas and argon as carrier gas/ion source for sputtering. The deposition has been achieved using direct current (dc) discharge power of 35W for sputtering and radio frequency (rf) power of 8–12W at substrate bias values in the ranges of −80 to −100V for polymerization. The composition of the film has been studied using infrared spectroscopy, Raman spectroscopy as well as X-ray photoelectron spectroscopy. The morphology of the film has been characterized with the help of a transmission electron microscopy and atomic force microscopy. The ultraviolet (UV) photo-stability of the composite film has been studied by exposing the film deposited on silicon substrate for different reaction times up to 1h under UV radiation at wave length ran