Investigation of laser‐produced plasma multistructuring by floating probe measurements and optical emission spectroscopy

Abstract

AbstractWith the continuous development of pulsed laser deposition as a versatile technique for the deposition of complex thin films, there is a need for a better understanding of the role and control of the deposition parameters. The understanding of the particle kinetics and plasma chemistry during the deposition process can greatly improve the properties of the synthesized films. By using the floating voltage regime of the Langmuir probe technique, we performed angular and time‐resolved measurements during laser ablation of an Ag target, which evidenced the structuring of the plasma plume in ultrahigh vacuum conditions. The addition of N2 gas in the pressure range from 5 × 10–5 to 10 Pa leads to more rapid plasma thermalization and the control of its kinetic energy. The electrical measurements were complemented by optical emission spectroscopy, which showcased the presence of neutral and multiple ionized species distributed across the laser‐produced plasma plume. The plasma homogenization resulted in a decrease of the mean free path of Ag ions and atoms, which increased both their excitation temperature and electron density.