Title :
Characterization of CuGaSe2 thin films grown by MOCVD
Author :
Orsal, Gaëlle ; Romain, Nahel ; Artaud, Marie-Claude ; Duchemin, Simone
Author_Institution :
Centre d´´Electron. de Montpellier, Univ. des Sci. et Tech. du Languedoc, Montpellier, France
fDate :
10/1/1999 12:00:00 AM
Abstract :
CuGaSe2 thin films have been grown by metalorganic chemical vapor deposition (MOCVD), from three organometallic precursors. Samples of about 1-2 μm thick are codeposited onto Pyrex and Mo-coated soda lime glass. A large range of compositions was investigated and characterized. Stoichiometric CuGaSe2 thin films are single-phased and their optical bandgap is about 1.68 eV. The features of the films are presented in relation with their composition. XRD spectra always exhibit a preferential orientation along the (112) plane. Secondary phases have been observed: Cu2Se for Cu-rich films, CuGa3Se5 for Ca-rich films. Observation of the morphology reveals larger polyhedral grains for Cu-rich films becoming platelet-shaped and tilted for Ga-rich compounds. The optical properties are also sensitive to the compositional changes and related to the eventual presence of binary phases. The gap increases with the Ga-content. The CuGa3Se5, phase exhibit a gap of about 1.85 eV. All the samples have a p-type conductivity
Keywords :
MOCVD; X-ray diffraction; copper compounds; gallium compounds; photonic band gap; semiconductor growth; semiconductor thin films; ternary semiconductors; 1 to 2 micron; 1.68 eV; CuGaSe2; MOCVD; XRD spectra; binary phases; optical bandgap; organometallic precursors; p-type conductivity; platelet-shaped grains; polyhedral grains; preferential orientation; Chemical vapor deposition; Conductivity; Glass; MOCVD; Morphology; Optical films; Optical sensors; Photonic band gap; Sputtering; X-ray scattering;
Journal_Title :
Electron Devices, IEEE Transactions on
