Structural transformation of CsI thin "lm photocathodes under exposure to air and UV irradiation
نویسندگان
چکیده
Transmission electron microscopy has been employed to study the structure of polycrystalline CsI thin "lms and its transformation under exposure to humid air and UV irradiation. The catastrophic degradation of CsI thin "lm photocathode performance is shown to be associated with the "lm dissolving followed by its re-crystallization. This results in the formation of large lumps of CsI crystal on the substrate surface, so that the "lm becomes discontinuous and its performance as a photocathode is permanently degraded. No change in the surface morphology and the "lm crystalline structure was observed after the samples were UV irradiated. ( 2000 Elsevier Science B.V. All rights reserved.
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