CUINSE2 THIN-FILMS GROWN BY MOCVD - CHARACTERIZATION, FIRST DEVICES

CuInSe2 (CIS) thin films have been deposited by MOCVD process, with co ntrolled thickness and composition. Copper precursors based on hexaflu oroacetylacetonato copper (Cu(hfa)(2)) have been specially developed. By varying the experimental parameters, a large range of compositions were investigated. Stoichiometric CIS layers present a high absorption in the visible range with an optical bandgap around 1 eV. When moving away from the stoichiometry, the films exhibit a mixture of two phase s. The Cu-rich films are composed of Cu2-xSe (x approximate to 0.15) a nd CIS while on the indium-rich side, the CuIn3Se5 phase is appearing along with CIS. This phase itself has also been obtained and character ized. The different properties of all these films are detailed. The fi rst solar cells, based on CIS grown by MOCVD, have been achieved. (C) 1998 Elsevier Science S.A. All rights reserved.