Influence of the counter ion on the properties of organic and inorganic acid doped polyaniline and their Schottky diodes

• Published in: Superlattices and microstructures 2015-09, Vol.85, p.282-293
• Main Authors: Ashokan, S., Ponnuswamy, V., Jayamurugan, P., Chandrasekaran, J., Subba Rao, Y.V.
• Format: Article
• Language: English
• Subjects: I–V characteristics; Polyaniline; Schottky diode; Supporting electrode
• ISSN: 0749-6036; 1096-3677
• DOI: 10.1016/j.spmi.2015.04.005

•Two types of In/PANI-DBSA/Al and In/PANI-HCl/Al heterojunctions diodes were fabricated.•The photoluminescence properties of pure and acid doped polyaniline were investigated and compared.•Comparative study of organic and inorganic acids doped rectifying effect.•Positive photoconductivity nature of the polyaniline. Pure and doped Polyaniline (PANI) was prepared by chemical oxidative polymerization of aniline. The FT-IR spectrum confirms the presence of dopants in PANI functional groups of SO32− groups in PANI. SEM morphology reveals the various shapes and size of the PANI. UV–Vis spectra confirm the absorption peaks at 270 and 340nm is due to the π–π∗ transition of the benzenoid rings. The strong absorption peak around 603nm showed extension of polymer chains. PL studies of PANI reveal the emission peaks around 325nm and 510nm of PANI. The conductivity measurements are carried out for the prepared PANI’s pellets. The heterojunction device structure In/PANI-DBSA/Al and In/PANI-HCl/Al was made to fabricate by thermal evaporation method. The current voltage (I–V) characteristics of these devices are weak rectifying behavior with the non-linear nature. The diode parameters such as ideality factor, barrier height and saturation current densities were calculated using the modified Shockley equation.