Real-time investigations of selenization reactions in the system Cu-In-Al-Se

In this article we present results of a detailed study of selenization reactions in the quaternary system Cu-In-Al-Se and of the binary subsystem aluminum-selenium. The investigation of solid-state reactions involved in the formation of the compound semiconductor Cu(In,Al)Se-2 was performed using real-time X-ray diffraction (XRD) with a time resolution of 22.5 s while annealing an elemental layer stack of the metals covered with selenium. A temperature-resolved phase analysis shows that the formation of the semiconductor takes place via metal-selenides. Ex-situ XRD measurements of the processed thin films show a phase segregation concerning the aluminum content of the formed chalcopyrite. Subsequent Rietveld-refinement of real-time measurements reveals a formation reaction of the quaternary semiconductor Cu(In,AI)Se-2 from the gamma-In2Se3 related crystal structure of (Al,In)(2)Se-3 and Cu2Se as educts. (c) 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.