CuInSe_2 films — base layers of solar cells: growth and structure

摘要

Solid-phase reactions in double-layered Cu/In_2Se_3 thin-film systems have been investigated by means of electron microscopy. The films have been grown by successive condensation of In_2Se_3 onto Cu in vacuum. The ratio of In_2Se_3 and Cu amounts determines the reaction succession. Cu + In_2Se_3 → Cu_2Se → α-, β-CuInSe_2 transitions have been observed as In_2Se_3 amount increased. Under Cu shortage and progressive increase of its amount, reactions Cu + In_2Se_3 → γ-phase→ β-CuInSe_2 → ?-CuInSe_2 take place. All observed phases are related to the pseudo-binary Cu_2Se-In_2Se_3 cross-section. CuInSe_2 layer formation is accompanied by recrystallization processes resulting in CuInSe_2 grain growth and recrys-tallization texture formation. Condensation play an important role in the CuInSe_2 film structure formation.