在本篇報告中我們展示了 Si05Ge05/Si超晶格發光二極體1.3~1.4微米的室溫電致發光頻譜。為了瞭解矽鍺能帶的結構，我們設計了純矽以及20%矽鍺的覆蓋層的發光二極體結構作為實驗 様品。實驗結果顯示了非常不同的LI特性以及光譜曲線。剛開始，在20%矽鍺的覆蓋層的發光二 極體中是由超晶格中價帶對導帶的載子復合。當注入電流增加時，兩個様品都顯示出來自矽材料與 超晶格結構的電致發光。但是矽發光頻譜的強度趨勢與矽層的厚度有關。LI曲線顯示了純矽覆蓋 層様品在主動區有比較少的電子濃度。根據室溫的結果，20%矽鍺覆蓋層的様品可能在擴散的電子 流前端存在一個小的阻擋層。實驗的結果顯示了矽鍺TypeII的能帶結構並因此局部地提高導帶電 子濃度使電致發光的效率增加。

In this report, room temperature electro-luminescence at 1.3-1.4 |xm from Si0.5Ge0.5/Si supperlattices light emitting diodes is demonstrated. Two samples with Si and Si0.8Ge0.2 capping layer are show very different characteristics on LI and spectral curves. At the first, the injection current is still low, the Si0.8Ge0.2 capped sample emitted light from supperlattices band to band recombination and typeII band offset recombination between Si and Si0.8Ge0.2 for 30K low temperature measurement. When the injection current increase, the two samples show Si and SLs emission. But, the intensity trend is indicated the Si emission intensity depend on its thickness of Si in the two sample. The LI curves reveal the sample with Si capping layer has less electron concentration in the active region. According to the room temperature results, the sample with Si0.8Ge0.2 capping layer has a small barrier in the front of electron current. We have demonstrated the type II between Si and Si0.8Ge0.2 can form a barrier to increasing Si emission intensity.