We present an experimental study of nonlinearity observed in a dc driven semiconductor-gas discharge system. The plasma glow is generated using planar electrodes in a vacuum chamber filled with nitrogen gas at partial atmospheric pressure. The discharge behaves oscillatory in time, showing single and sometimes multiple periodicities in plasma current and voltage measurements. Harmonic frequency generations and period doubling cascade are investigated experimentally by varying the applied voltage. To identify the stability condition, numerical simulations are conducted using COMSOL® Multiphysics software. The discharge is modeled as a one dimensional plasma slab. Numerical results are in good agreement with the experimental measurements.

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Fluorene‐type (C13H10) thin films were synthesized by using the mixture of biphenyl (C12H10) and methane (CH4) plasma. The reactor is a parallel plate installation; upper electrode is connected to 13.56 MHz rf power and lower electrode is grounded. The thin films were deposited by applying a negative bias potential between the substrate and the wall of reactor. The films were investigated by residual gas analysis (RGA), UV–vis spectroscopy, atomic force microscope (AFM) and ellipsometry. They had significant nanostructured properties which were suitable for photovoltaic applications. The conjugation was improved by iodine doping and the optical band gap energy dropped down up to 2.85 eV.

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