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 degrees C. The CuSe(2) phase returned to CuSe by releasing Se at its peritectic point of 330 degrees 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). (C) 2011 Published by Elsevier B.V.