| Summary: | 碩士 === 南臺科技大學 === 電子工程系 === 106 === In this study, we investigate the performance of various characteristics of GaN series light-emitting diodes(LED) by Time Resolved Electroluminescence System (TREL)，including high-frequency and low-frequency response decay rates, and the rising time and falling time at each frequency. Inferred the main characteristics affecting the frequency response of GaN series LED, then find a solution to enhance the response frequency.
In this experiment, we have two groups of samples, one is the blue light-emitting diode have an electronic retardation layer compared to no electron retardation layer. In the light output, inserting the electron retarding layer can increase the light output. However, the part of the frequency response at low current will also decrease the speed due to the retardation layer, and the high-frequency response will also decrease significantly. The second group is the near-ultraviolet light-emitting diodes of the superlattice electron blocking layer with different composition ratios. Each sample capacitance difference is quite obvious, the high capacitance samples have longer rising time and falling time, this causes the high frequency response rate to drop rapidly.
In the result, we found that the frequency response of GaN LED can be improved by increasing the amount of electron injection. When there are fewer defects, more carriers are injected into the active layer, and the smaller capacitance, the faster the saturation, so the faster the GaN LED reacts.
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