研究期間：10108~10207;Presently, the applications of the LED are focused in the lighting field. The improvement of luminous efficiency is a main issue. The efficiency of the LED chip still needs to be increased. The light and electric characteristics are significantly influenced by the temperature distribution inside the chip. Via the proper chip design with the consideration of the heat and electricity coupling effects, the chip has uniform distribution of current, smaller driving voltage and uniform distribution of heat. The less heat generation on the chip and the well dissipation of heat will improve the efficiency of the LED. This study is expected to contribute the numerical simulation model, which can demonstrate every characteristic of LED chip. The voltage, current distribution, heat generation, temperature distribution, and light-source distribution are the characteristics discussed. The above- mentioned characteristics would influence each other. Then according to the numerical simulating results, electrode optimization design and heat dissipation mechanism are determined. Besides, the manufacturing technology for AC/HV LED is progressive, and the commercial products of AC/HV LED are in the market recently. The situation of heat generation in AC/HV LED is different from that in conventional LED. But few literatures have mentioned about the thermal issue of AC/HV LED or the influence of heat on electrical and optical characteristics of them. The above-mentioned numerical simulation model of LED chip is also used to simulate the temperature distribution during AC operations of an AC/HV LED in this project, and find out proper electrode pattern and operating parameter for an AC/HV LED. Then the light characteristic form LED chip will be substituted into the numerical model for phosphor to calculate the percentages of light absorption and re-radiation. The experimental equipments for measuring the thermal resistance of AC/HV LED and the photoluminescence system will be set up during this project.
