| Summary: | 碩士 === 國立暨南國際大學 === 應用材料及光電工程學系 === 101 === This study combines bias measurements with a focused ion beam (FIB), optical measurements, electroluminescence and MATLAB, to observe light-emitting on the surface of the blue light emitting diodes nitrogen dioxide (Gallinm nitride, GaN) and blue light emitting diodes with indium gallium nitride (InGaN) under reverse bias. We have strong interested in reverse bias emitting, and people doesn’t fully understand light-emitting diodes emitting defects, in order to nimble and expedite testing time in operation, and indicate defect GaN light-emitting diode (LED) briefly. We schemed a stress test which is controlled in water vapor and under reverse-bias, the device degradation at room temperature is very quick. Under water vapor after 200 minute, the LEDs device exhibited remarkably higher oxygenation in EDX analysis and morphological variation in SEM compared to the other sample operated at normal atmosphere. Current-voltage curve (I-V) were used to make analysis of the electrical properties to acquire the threshold voltage and leakage current. We also deal with surface temperature measurement and 2D electroluminescence (EL) images via Matlab to ascertain the relation between leakage current and reverse-bias luminescence. These techniques were proposed to depict an actual optical degradation and detect the device defects with the fabrication process for future industrial applications.
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