Studying the energy characteristics of laser erosion plasma of a CuInSe₂ target by time-resolved emission spectroscopy

Abstract

The most intense spectral lines of In I (271.0, 293.3, 303.9, 410.2, 451.1 nm) and Cu I (324.8, 327.4, and 521.8 nm) emitted from the plasma plume of the laser erosion of a polycrystalline CuInSe₂ target have been studied by time-resolved emission spectroscopy at a distance of 1 mm from the target. The kinetics of the spectral line intensity exhibits two maxima, the first of which is more pronounced for transitions from upper excited atomic states, while the second is more pronounced for transitions from lower energy states. It is established that the velocity of indium atoms in the plasma plume (83 and 14 km/s for species contributing to the first and second maximum, respectively) is greater than the corresponding velocities of copper atoms (63 and 12 km/s); the recombination time of singly charged indium ions (56 ns at a time of about 200 ns upon excitation) is smaller than that of singly charged copper ions (139 ns at a time of about 250 ns).