Cu(InGa)Se2 thin film photovoltaic absorber formation by rapid thermal annealing of binary stacked precursors

Abstract Phase evolution during the synthesis of Cu(InGa)Se 2 from glass/Mo/(In 1 − x Ga x ) 2 Se 3 /CuSe bilayer precursors were investigated by in-situ high-temperature X-ray diffraction. With Se overpressure, CuSe was transformed to CuSe 2 at 220 °C. The CuSe 2 phase returned to CuSe by releasing Se at its peritectic point of 330 °C, where the formation of Cu(InGa)Se 2 phase was initiated as well. Rapid thermal processing of bilayer precursors showed the potential of fast formation of Cu(InGa)Se 2 within 2–5 min reaction with fairly uniform Ga and In depth profile. Further annealing with Se overpressure caused the formation of MoSe 2 at the interface of Mo and Cu(InGa)Se 2 .