Defects in CdTe polycrystalline films grown by physical vapour deposition

CdTe films were grown by physical vapour deposition onto alumina, glass and silicon substrates. The best growth conditions were a source temperature in the range 700–830 °C, a substrate temperature from 450 to 550 °C and a growth time of about 4 h. Onto alumina and glass the films grow with the [111] axis perpendicular to the substrate. Tellurium inclusions were found as the main film imperfection. Film thickness from 20 to 150 μm was determined by profilometry. Photoluminescence measurements confirmed the high quality of the films. They show resistivities in the order of 106 Ω cm. A comparison with previous reported data and an evaluation about the X-ray imaging capabilities of the films are included.