Control of the crystal structure and electrical transport in undoped PbTe films grown by pulsed laser deposition

Lead telluride (PbTe) undoped films with various thicknesses (40-1800 nm) were grown by pulsed laser deposition (PLD) on different single crystal substrates (KCl, Si) and at different substrate temperatures (30 °C, 200 °C). Structural and electrical investigations of the so-obtained films have been carried out. The growth conditions leading to the films having different properties that could be controlled in a possibly wide range were identified. The film crystal structure varied from pseudo-amorphous to a highly ordered one. The films exhibited semiconducting behavior except the case of the thinnest, metallic-like layers. Electrical transport properties of the films with different structural quality were affected by changes of the grain boundary-related potential barrier height whereas donor level-related activation energies remained unchanged.