Room Temperature Direct Band-Gap Emission from an Unstrained Ge P-I-N LED on Si
Room Temperature Direct Band-Gap Emission from an Unstrained Ge P-I-N LED on Si
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DOI：
10.4028/www.scientific.net/ssp.178-179.25
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发表时间：
2011-08
期刊：
影响因子：
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通讯作者：
T. Arguirov;M. Kittler;M. Oehme;N. Abrosimov;E. Kasper;J. Schulze
中科院分区：
文献类型：
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作者：
T. Arguirov;M. Kittler;M. Oehme;N. Abrosimov;E. Kasper;J. Schulze
我们提出了一种新型的硅基锗发光二极管与非应变i-Ge有源区。该器件在室温下工作，并发射能量为0.8 eV的光子。它基本上类似于在亚微米薄Ge层上形成的p-i-n结构。Ge层是利用薄的虚拟缓冲层生长在Si衬底上的，因此它是无应力的，但具有高的穿透位错密度。我们表明，这种正向偏置二极管产生强烈的发射，所造成的直接带间跃迁锗。使用基于InSb的探测器，我们能够在宽的能量范围内分析发射光谱。我们表明，在低和中等电流，属于直接和间接的带电子跃迁的功能是存在的特征锗。明显占主导地位的是直接跃迁相关峰。由于缺少与应力相关的红移，该峰看起来接近所需的通信波长1.55 μm。辐射强度对激发电流的依赖性遵循指数为1.7的幂低，表明竞争性非辐射过程的复合率相对较低。在高激励电流的特点出现在低能量的频谱的一部分。所有的结果在这里进行了讨论，鉴于从测量结果的Ge高品质块体材料。讨论了位错在Ge薄膜中的作用。
We present a novel Ge on Si based LED with unstrained i-Ge active region. The device operates at room temperature and emits photons with energy of 0.8 eV. It basically resembles a p-i-n structure formed on a sub-micrometer thin Ge layer. The Ge layer has been grown on Si substrate by utilizing thin virtual buffer, so it becomes stress free but with high threading dislocation density. We show that such forward biased diode generates strong emission, caused by direct band to band transition in Ge. Using an InSb based detector we were able to analyze the emission spectrum in a broad energy range. We show that at low and moderate currents, features belonging to the direct and the indirect band to band electronic transitions are present which are characteristic for Ge. Clearly dominating is the direct transition related peak. Due to the missing stress-related red shift this peak appears close to the desired communication wave length of 1.55 μm. The dependence of radiation intensity on the excitation current follows a power low with exponent of 1.7, indicating that the recombination rate of the competitive nonradiative processes is relatively low. At high excitation currents features appear in the low energetic part of the spectrum. All results presented here are discussed in view of the outcome from measurements on Ge high quality bulk material. The role of the dislocation in the Ge films is discussed.