Vacuum 80 (2006) 841–849 Plasma dynamics studies during deposition of thin film PbTe on a glass substrate E. Rodriguez à , E. Jimenez, L. Moya, C.L. Cesar, L.P. Cardoso, L.C. Barbosa Departamento de Eletroˆnica Quaˆntica, Instituto de Fı´sica ‘‘Gleb Wataghin’’, Universidade Estadual de Campinas, P.O. Box 6165, CEP 13084-971, SP, Brazil Abstract PbTe thin films were prepared by pulsed laser deposition using a Nd:YAG laser (532 nm) in an argon atmosphere. Dynamic processes in the gas phase induced by Nd:YAG laser ablation of PbTe are investigated by analyzing the light emitted by the plume. Pressure in the chamber varied from 1.0  10 5 to 1.0 mbar. Space and time-resolved optical spectroscopy measurements indicate the presence of both neutral, Pb(I) and Te(I) and ionized, Pb(II) and Te(II), species. The velocities of the species remain unchanged for argon pressures up to 10 1 mbar, which suggests that expansion of the plume occurs without further collision with the foreign gas in this pressure range. It is found that an addition of 5  10 1 mbar Ar enhances the emission line intensity and leads to a decrease in species velocity observed at large distances from the target surface. Furthermore, a region of maximum emission intensity at distance of 5–10 mm from the target is found when a gas environment is present. r 2005 Elsevier Ltd. All rights reserved. 1. Introduction Lead telluride belongs to the group of A IV B VI semiconductors which crystallize in the FCC NaCl-type structure under ambient conditions. This material exhibits properties, which are unusual, and possibly unique, relative to other semiconductors. For instance, it possesses a high dielectric constant, high carrier mobility and a narrow fundamental band gap E 0  0.3 eV whose temperature coefficient (dE 0 /dT) is positive [1]. This material has also been the subject of many research efforts, due to the technological importance for its use in a variety of opto- electronic device applications like infrared detectors and tunable mid-infrared quantum well diode lasers [2]. More recently, PbTe grown in the form of quantum dots has been studied because of attendant non-linear optical properties [3]. The fact that PbTe exhibits quantum confinement effects in the region used for optical communica- tions [4,5] makes this material an excellent candidate for developing switching devices [6]. ARTICLE IN PRESS www.elsevier.com/locate/vacuum 0042-207X/$ - see front matter r 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.vacuum.2005.07.005 à Corresponding author. Tel.: +55 19 3788 5452; fax:+55 19 3788 5427. E-mail address: eugenio@ifi.unicam.br (E. Rodriguez).