Spectroscopic diagnostic of an argon-hydrogen RF inductive thermal plasma torch at atmospheric pressure used for silicon hydrogenation

Hydrogenation of silicon materials has great advantages for its photovoltaic properties and is the key to elimination of crystalline defects during basaltic growth of the crystal. It is therefore interesting to characterize the plasma by optical emission spectroscopy methods in order to study hydrogenation of silicon particles during their treatment by an inductive thermal plasma burning in the Ar-H-2 mixture. Excited states of atomic hydrogen n' = 3-8, which are responsible for silicon hydrogenation, have been detected by the optical emission spectroscopy of the Balmer series lines. These hydrogen lines have been used to determine electronic density on the plasma axis. Furthermore, Ar I lines were used to estimate the electronic temperature by the Boltzmann plot method. The deviation from the local thermodynamic equilibrium of the plasma has also been estimated.