Epitaxial CuInSe2 thin films grown by molecular beam epitaxy and migration enhanced epitaxy

• Autor(a) principal: Abderrafi, K.
• Data de Publicação: 2017
• Outros Autores: Ribeiro-Andrade, R., Nicoara, N., Cerqueira, M. F., Gonzalez Debs, M., Limborço, H., Salomé, P. M. P., Gonzalez, J. C., Briones, F., Garcia, J. M., Sadewasser, S.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/1822/48546
• topic: CuInSe2; molecular beam epitaxy; migration enhanced epitaxy; Semiconducting ternary compounds; Crystal structure; Surface structure; A1: Crystal structure; A1: Surface structure; A3: Migration enhanced epitaxy; A3: Molecular beam epitaxy; B2: Semiconducting ternary compounds; Engenharia e Tecnologia::Engenharia dos Materiais; Science & Technology

While CuInSe2 chalcopyrite materials are mainly used in their polycrystalline form to prepare thin film solar cells, epitaxial layers have been used for the characterization of defects. Typically, epitaxial layers are grown by metal-organic vapor phase epitaxy or molecular beam epitaxy (MBE). Here we present epitaxial layers grown by migration enhanced epitaxy (MEE) and compare the materials quality to MBE grown layers. CuInSe2 layers were grown on GaAs (001) substrates by co-evaporation of Cu, In, and Se using substrate temperatures of 450 ºC, 530 ºC, and 620 ºC. The layers were characterized by high resolution X-ray diffraction (HR-XRD), high-resolution transmission electron microscopy (HRTEM), Raman spectroscopy, and atomic force microscopy (AFM). HR-XRD and HR-TEM show a better crystalline quality of the MEE grown layers, and Raman scattering measurements confirm single phase CuInSe2. AFM shows the previously observed faceting of the (001) surface into {112} facets with trenches formed along the [110] direction. The surface of MEE-grown samples appears smoother compared to MBE-grown samples, a similar trend is observed with increasing growth temperature.