New pathways for nanoparticle formation in acetylene dusty plasmas: a modelling investigation and comparison with experiments

In this paper, the initial mechanisms of nanoparticle formation and growth in radiofrequency acetylene (C 2 H 2 ) plasmas are investigated by means of a comprehensive self-consistent one-dimensional (1D) fluid model. This model is an extension of the 1D fluid model, developed earlier by De Bleecker et al . Based on the comparison of our previous results with available experimental data for acetylene plasmas in the literature, some new mechanisms for negative ion formation and growth are proposed. Possible routes are considered for the formation of larger (linear and branched) hydrocarbons C 2 n H 2 ( n = 3, 4, 5), which contribute to the generation of C 2 n H − anions ( n = 3, 4, 5) due to dissociative electron attachment. Moreover, the vinylidene anion (H 2 CC − ) and higher anions ( n = 2–4) are found to be important plasma species.