Atmospheric-pressure DBD plasma modifying photoemission, optical and electrical properties of polycarbonate films

In this study, the DBD plasma reactor has been constructed, characterized, and tested to be employed in material treatment for use in different applications. A neon power source with an output of 10 kV, 30 mA, with a frequency of 20 kHz is used to drive the DBD reactor in an atmospheric -pressure environment. The investigation covered the analysis of many parameters of the dielectric barrier discharge (DBD) reactor, including its discharge voltage, current, capacitance, consumption energy, and the light emission of the produced plasma. Also, to examine the generated DBD plasma effect, the photoemission, optical, and electrical characteristics of untreated/ treated polycarbonate films were investigated using photoluminescence spectroscopy, UV/Vis spectroscopy, and electrical spectroscopy. The results demonstrated the appearance of two modes in the DBD discharge: filamentary and homogeneous. Moreover, the DBD reactor's power consumption has been measured to be 20 mW at a supplied voltage of 6.5 kV peak -to -peak, operated in atmospheric-pressure. The photoluminescence emission results emphasized that the treated films are modified particularly with increasing DBD treatment time. The UV-Vis spectra demonstrated a notable displacement of the absorption edge towards higher wavelengths as the duration of DBD exposure increased. This is indicative of the reduction of the band gap energy, thus improving the electric conductivities. The optical parameters of the treated polycarbonate films were enhanced in comparison to the untreated sample. Through the used frequency range, measurements of dielectric loss, dielectric constant, as well as AC electrical conductivity, are sensitive parameters to the modifications in electrical behaviors due to DBD plasma treatment.