Growth defects in CuInSe2 thin films

Abstract
CuInSe2 thin film solar cells with an efficiency of about 10% were studied with a cross-sectional high resolution transmission electron microscope (HRTEM). The growth defects such as twins, stacking faults, and intergrowth phase in the CuInSe2 thin films were studied in detail. Polycrystalline CuInSe2 films were deposited on a Mo-coated glass substrate by using the three source evaporation system. The CuInSe2 film contains fivefold multiply twinned crystallites as well as a high density of twins in the {112} plane. The CuInSe2 film also contains intergrowth phase with a long range of periodicities of 10 Å parallel to the [112] direction of the chalcopyrite structure. The intergrowth phase composition is similar to the chalcopyrite phase. The structural model of the intergrowth phase is proposed on the basis of the high resolution electron micrograph.
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