了解導(dǎo)致在高亮度LED的衰落

　　高亮度發(fā)光二極管不會(huì)迅速熄滅。相反，它們慢慢地消失了。一個(gè)精心設(shè)計(jì)的LED照明系統(tǒng)可以看到光源持續(xù)長(zhǎng)達(dá)50000小時(shí)，甚至70000小時(shí)之前，照明已經(jīng)不足以滿足預(yù)期的工作。

　　是什么原因使芯片失去亮度，可以采取任何措施來阻止下降嗎？本文回顧了LED光子產(chǎn)生背后的物理現(xiàn)象，探討了器件新出現(xiàn)的情況，以及為什么芯片壽命不可避免地會(huì)惡化。

　　本文還將討論什么設(shè)計(jì)工程師可以做到最大化，在他們的下一個(gè)設(shè)計(jì)LED的壽命和鑄一眼什么主要的LED供應(yīng)商如Cree公司，歐司朗，漢城半導(dǎo)體在提高商業(yè)產(chǎn)品的下一代。

　　Basic properties

　　Constructing an LED is relatively simple; choose appropriate n- and p-type semiconductors， bring them together to form a p-n junction or diode， connect the n-type to the negative terminal of a power supply and the p-type to the positive， and wait for things to start glowing.

　　The n-type semiconductor contains free electrons， while the p-type has electron vacancies or “holes.” The electrons and holes carry opposite charges and， under the bias voltage， migrate to the junction between the two materials where they can recombine. That recombination （sometimes） releases light in the visible part of the spectrum in a physical phenomenon known as electroluminescence.