All-Group IV Transferable Membrane Mid-Infrared Photodetectors
All-Group IV Transferable Membrane Mid-Infrared Photodetectors
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DOI：
10.1002/adfm.202006329
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发表时间：
2020-10-07
影响因子：
19
通讯作者：
Moutanabbir, Oussama
中科院分区：
文献类型：
--
作者：
Atalla, Mahmoud R. M.;Assali, Simone;Moutanabbir, Oussama
半导体膜作为一种多功能的纳米材料出现，以控制晶格应变和工程复杂的异质结构，使各种创新的应用。从这个角度来看，在此利用该平台来同时调谐IV族GeSn半导体合金中的晶格参数和带隙能量。随着Sn含量增加以达到直接带隙，这些半导体变得亚稳态并且通常压缩应变。结果表明，在释放膜的弛豫扩展吸收波长范围更深的中红外。完全释放的Ge（0.83）Sn（0.17）膜集成在硅上，用于制造在室温下工作的宽带光电探测器，记录截止波长为4.6 μ m，而不会影响低至2.3 μ m的较短波长下的性能。这些膜器件的特征在于暗电流的两个数量级的减少相比，生长应变外延层。各种实验工具和优化计算用于讨论的结晶质量，成分均匀性，晶格应变，和电子能带结构的研究材料和设备。设计所有IV族可转移中红外光电探测器的能力为利用这些集成的硅兼容应变弛豫GeSn膜实现可扩展和灵活的传感和成像技术奠定了基础。
Semiconductor membranes emerged as a versatile class of nanomaterials to control lattice strain and engineer complex heterostructures enabling a variety of innovative applications. With this perspective, herein this platform is exploited to tune simultaneously the lattice parameter and bandgap energy in group IV GeSn semiconductor alloys. As Sn content is increased to reach a direct bandgap, these semiconductors become metastable and typically compressively strained. It is shown that the relaxation in released membranes extends the absorption wavelength range deeper in the mid-infrared. Fully released Ge(0.83)Sn(0.17)membranes are integrated on silicon and used in the fabrication of broadband photodetectors operating at room temperature with a record wavelength cutoff of 4.6 mu m, without compromising the performance at shorter wavelengths down to 2.3 mu m. These membrane devices are characterized by two orders of magnitude reduction in dark current as compared to as-grown strained epitaxial layers. A variety of experimental tools and optimized calculations are used to discuss the crystalline quality, composition uniformity, lattice strain, and the electronic band structure of the investigated materials and devices. The ability to engineer all-group IV transferable mid-infrared photodetectors lays the groundwork to implement scalable and flexible sensing and imaging technologies exploiting these integrative, silicon-compatible strained-relaxed GeSn membranes.