AVS 56th International Symposium & Exhibition
    Advanced Surface Engineering Monday Sessions
       Session SE-MoA

Paper SE-MoA8
Diagnostic Study of an Arc Plasma Jet Under Atmospheric Pressure and Its Applications to Materials Processing

Monday, November 9, 2009, 4:20 pm, Room C4

Session: Atmospheric Pressure Plasmas
Presenter: C.C. Hsu, National Taiwan University
Authors: C.C. Hsu, National Taiwan University
C.Y. Wu, National Taiwan University
Y.W. Hsu, National Taiwan University
Y. Lin, National Taiwan University
Y.J. Yang, National Taiwan University
Correspondent: Click to Email
An atmospheric-pressure arc plasma jet was studied, and its use for material processing will be presented. This plasma jet was sustained by a DC pulsed power source of 20 kHz ~ 40 kHz using nitrogen. A voltage probe and a current probe were used to monitor the voltage and current (I-V) waveforms. The optical emission at the plasma jet downstream was monitored by an optical emission spectrometer. Multiple thermocouples were used to measure the downstream jet temperature. The I-V waveforms reveal that the jet undergoes abnormal glow to arc transition within each pulse power period. This transition is shown to be critical for sustaining a stable plasma jet and is primarily controlled by the power input to the plasma in the abnormal glow regime. Temperature and optical emission measurements show that the jet temperature decreases and the excited-state species densities increase with the increase of the gas flow rate, while both quantities increase with the increase of the applied voltage. These allow for the independent control of the temperature and the excited-state species densities by using these two operating parameters. The use of this plasma jet for materials processing, namely zinc oxide thin-film deposition and niobium oxide nanowire fabrication, will be presented. The correlation between the plasma behavior and the fabricated materials characteristics will be discussed.