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CuInSe2 thin films deposited by a hybrid process combining magnetron sputtering of Cu and In with evaporation of Se have been analyzed and solar cells have been fabricated. The hybrid technique is shown to produce CuInSe2 films of device quality. Heterojunction Mo/CuInSe2/CdS/ITO/Ni devices with photovoltaic conversion efficiencies as high as 7.7% have been tested. Device characteristics for the best device include VOc = 0.385 V, Jsc = 32.6 mA, and a fill factor of 61.3 %. The device required an air anneal to achieve full efficiency. Results of microstructural analyses using transmission electron microscopy are reported which assist in determining what limits the performance of these devices. Asdeposited CuInSe2 exhibits no measurable differences as compared with CuInSe2 produced by three-source evaporation. All films contain microtwins, stacking faults, and voids. No evidence was found for second phases in material with metal atom fractions as much as four percent off of stoichiometry. Defect-ordering produces features in the diffraction patterns of single-phase material at positions not normally allowed for the chalcopyrite structure. These measurements are compared with results for single crystals grown by the vertical Bridgeman method by Tomlinson. X-ray photoelectron spectroscopy results are also presented characterizing the valence band as a function of film composition.