溫度對高功率LED發光性質之研究

A STUDY OF LUMINOUS PERFORMANCE OF LED WITH HIGH INTENSITY AFFECTED BY TEMPERATURE

杜國強(Kuo Chiang Tu)

指導教授 ： 劉宗平

元智大學/電機通訊學院/電機工程學系/碩士(2009年)

摘要

隨著節能的要求，LED照明已普遍的應用於日常生活之中。由於LED具有體積小、發光效率佳、壽命長、省電、環保等特質，因此隨著綠色能源之訴求，LED照明已逐漸受到市場上的青睞與重視。本論文即在探討溫度對高功率LED光學特性所造成的影響。
在此研究中，先分別針對紅光、綠光及藍光LED，藉由溫度的改變，利用積分球量測出各LED的光學特性；探討其相應的電流對電壓之變化曲線。其次，針對紅、綠、藍三原色混光而成的LED，在溫度各為 10℃、50℃ 及90℃的條件下，探討電氣特性及光學特性隨溫度的變化。實驗結果顯示，光強峰值相應之波長有紅移或藍移的現象。然後，經由個別調整各單色光LED的輸入電流來維持相對穩定的色溫及演色性，接著再對藍光晶片刺激螢光粉產生白光的LED。在溫度為 10℃、50℃ 及90℃的條件下，利用積分球量測其光學特性。從各項光學數據之表現。來探討溫度對藍光晶片刺激螢光粉產生白光的效應。
在實際設計LED照明產品時，須先考慮溫度對LED特性的影響，以降低設計開發的成本、縮短設計開發的時間，減少不必要的浪費。本研究之結果可提供業界參考，作為探討溫度對LED光學特性影響的依據。

關鍵字

發光二極體；照明 ；波長漂移

並列摘要

Due to the energy saving demand growth, the light emitting diode (LED) has been widely applied to the daily life. The LED chip possesses advantages such as impact size, high efficiency, long life time, power saving, and environmental friendly. Because the green energy is being important, the LED solid-state lighting technique is widely spreading. In this thesis, the electrical and optical performances of high power LED effected by temperature are investigated.
At the first, as temperature is increasing, the relation between the injection current versus forward voltage of red, green, and blue LEDs are measured by using an integral sphere to obtain their optical performance. Next, electrical and optical properties of LED composed of red, green, and blue chips varied with temperature are measured at different temperatures of 10, 50, and 90 ?C, respectively. Through measurements, they show that the wavelength corresponding to the peak value of light intensity would be red-shift or blue-shift as temperature changed. The specific color temperature and color rendering can be maintained by modulating the injection currents of each LED chip. Under the condition of the same temperature, yellow phosphors excited by blue LED to produce white light to study electrical and optical properties varied with temperature.
The fabrication cost and developing time of LED module can be significantly reduced by governing the performance of LED chips affected by temperature. The results of this paper can be provided to the industry for LED lighting.

並列關鍵字

LED ； illumination ； wavelength shift

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