Effect of Gold Nanoparticles on the Physical Properties of Poly (3,4- ethylenendioxythiophene): Poly (styrene sulphonate) and its Gas Sensor Application

Conducting polymers offer a unique combination of properties that make them promising candidate materials for electronic applications. Poly (3,4 - ethylene dioxy thiophene): poly(styrene sulphonate) (PEDOT-PSS) is one of conducting polymers that has excellent qualities to be incorporated into many organic devices as helping in the charge transfer. In this study, different sizes of gold nanospheres (Au NSs) have been embedded into the PEDOT-PSS to improve its physical properties by forming nano composites. Au NSs, which exhibit tunable absorption depending on their size, have effectively improved the absorbance of PEDOT-PSS. The energy gap and the Urbach energy of PEDOT-PSS have decreased from 3.45 eV and 2566 MeV, respectively, to be 3.36 eV and 2262 MeV, respectively, for the biggest size of (Au NSs) embedded in PEDOT-PSS. Also, the absorption edge value of the nano composite with the biggest size was 3.05 eV whereas PEDOT-PSS has the value of 3.46 eV. Embedding Au NSs in PEDOT-PSS has caused an enhancement of the electrical conductivity of the produced nano composites. Lowering the gas sensitivity of PEDOT-PSS to volatile organic compound (VOCs) by embedding it with (Au NSs) can suggest this nano composite to be applied in electronic devices