Desevolvimento de dispositivos eletrônicos orgânicos nano e micro-estruturados: memória volátil, sesores e fotocélulas

Abstract

In this work, several nano and microstructured organic devices were developed based on molecules of 4-dimethyl amino azobenzene-2-carboxylic acid (Methyl Red – VM), C60 Fullerene, nanocomposite of Aluminum/Carbon Nanotubes (Al/NC) and polymers: Poly(3, 4- dioxithiophene ethylene)-poly(sulfonate stireno) – PEDOT-PSS and poly(3-hexiltiofeno) – P3HT. These devices are volatile memory, fuel sensors, thermal-piezoresisitive sensor and photocells, which were manufactured by spin-coating, drop casting and chemical vapor deposition, resulting in devices with planar or layer by layer geometry. Morphological, optical, electrical and thermal characterizations were performed on devices, resulting: (a) volatile memory with a bit retention time of 4.5 s, the characteristic curves of current vs. voltage with peak-valley ratios of 8: under a 10:1 voltage positive and negative electrical energized with electrical conductivity of 10-4 S / m (OFF state) to 3.10 S / m (ON) at room temperature, (b) fuel sensors like chemiresistor sensors characteristics with sensitivity to ethanol and gasohol in concentrations of 26.25 ppm, (c) thermal-piezoresistive sensor with polynomial relationship between temperature and electrical resistance, linear relationship between pressure and electrical resistance, more accurate than a K type thermocouple when compared to a mercury thermometer at room temperature, (d) photocells with better performance when doped by Methyl Red showed quantum efficiencies up to 0.04%, real power at 0.27 and power conversion efficiency of 2.0%. These results indicate that electronic devices developed showed a better performance in comparison to similar organics.