Two CuGaSe2 films were grown by molecular beam epitaxy onto GaAs (001) substrates with varying Cu/Ga flux ratios under Se overpressure conditions. Growth was interrupted at predetermined times and the surface composition was measured using Auger electron spectroscopy after which growth was continued. After growth, the film composition was analyzed using voltage dependent electron microprobe spectroscopy. Film structure and morphology were also analyzed using x-ray diffraction and atomic force microscopy. The film with a Cu/Ga ratio larger than unity showed evidence of surface segregation of a second Cu-rich phase with a Cu/Se composition ratio slightly greater than unity. A second CuGaSe2 film with a Cu/Ga ratio of less than unity showed no change in surface composition with time and was also consistent with bulk composition measurements. Diffraction measurements indicated a high concentration of twins as well as the presence of domains with mixed c and a axes in the Ga-rich film. The Cu-rich films by contrast were single domain and had a narrower mosaics. High sensitivity scans along the  reciprocal axis did not exhibit any new peaks not attributable to either the substrate or the CuGaSe2 thin film.
|ジャーナル||Materials Research Society Symposium - Proceedings|
|出版ステータス||Published - 1998 1月 1|
|イベント||Proceedings of the 1997 MRS Fall Meeting - Boston, MA, USA|
継続期間: 1997 12月 2 → 1997 12月 5
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