Pulsed plasma polymerization of thiophene

Highly transparent (>80%) and conductive layers (10(-6) S/cm) were obtained by the pulsed plasma polymerization of thiophene. The influence of power, pressure, pulse time, duty cycle, and position in the reactor on the conduc tivity of the resulting plasma polymerized thiophene (PPT) layers was evalu ated. In the used ranges, only pressure had a significant influence on the conductivity of the deposited layer. The results could be correlated to the effect of the deposition parameters on the fragmentation of the thiophene monomer. At high pressure there was less fragmentation of thiophene, result ing in a higher conductivity of the layer. It was shown that the use of a p ulsed plasma as a means to minimize fragmentation is most efficient when th e off time is chosen such that the reactor is replenished with new monomer during the off period.