Executive Summary : | Objective: Indigenous development of plasma cleaning and spray pyrolysis equipment’s for TCO and metal oxide depositions partnering with industry; Development of low temperature process for FTO deposition by fine tuning sol compositions and process sourcing locally available soda-lime glass; Synthesis and fine tuning the composition F/Sn ratios to achieve higher conductivity and better transparencies at lower processing temperatures; Optimization of flow rate of precursor solution, deposition time, height of deposition etc. to achieve a uniform coating over a substrate area upto 30cm x 30cm involving glass and metal substrates; Development of FTO layers with varied thickness and optimized grain size leading to lower grain boundaries, better transparencies and higher electronic conductivities Summary: Transparent , conducting oxide (TCO) materials have been known for a long time out of which large band gap (Eg > 3.0 eV) semiconducting material, F-doped SnO2 (FTO) occupies a prominent position as it finds an array of application in potential and emerging sector of Photovoltaic, Lighting Devices (LEDs, OLEDs), Electrochromic Devices etc. Conventionally TCO layers can be deposited by techniques such as chemical vapor deposition (CVD), electron beam evaporation, pulsed laser deposition,RF magnetron sputtering ,atomic layer epitaxy , spray pyrolysis ,and sol-gel processes. Among these techniques , spray pyrolysis is a simple technique , which can be used to prepare large-area films with uniform morphology having good electrical properties .the lead investigator is already having patents flied in this area .As per the technology development forecast document published by TIFAC, dst, Govt of India ,development of transparent conducting coating is of national interest and priority.
Currently in India we are not having indigenous equipment and manufacturing of FTO substrates. For all optoelectronic research and applications, we import FTO from abroad which result in huge financial burden as in most cases FTO are deposited on high quality glass. Additional, batch to variation, quality and time taken for delivery of martials stands as constraints to meet the deliverables in many cases. In this regard, partnering with a start –up company having experience in coating technologies [Delgado coating & Technology solution], CSIR_NIIST wanted to initiate this unique activity of development of a custom designed unique spray pyrolysis equipment for FTO coating on glass with maximum size up to 30cm*30cm catering to the needs of R&D institutions and industries. We will be custom designing the equipment’s required sols and process in such a way to use the locally available soda lime glass, thereby reducing the cost to a greater extent. NIIST will also deliver a complete turn- key solution by development the supply chain of Martials (sols) with optimized process that provides higher conductivities without compromising the transparency. Delgado had already shown interest in future commercialization of such equipment’s and development sols. This project will give CSIR-NIIST and Delgado to step=into addressing a unique problem which limits the commercialization due to higher price in various optoelectronic sectors. The expression of interest letter from Delgado for this joint co-development and their willingness to license this technology in future is attached at the end of this proposal. |
