Ferroelectric Enhanced Performance of GeSn/Ge Dual-nanowire Photodetector.
Ferroelectric Enhanced Performance of GeSn/Ge Dual-nanowire Photodetector.
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DOI：
10.1021/acs.nanolett.0c01039
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发表时间：
2020-04
期刊：
影响因子：
10.8
通讯作者：
Yuekun Yang;Xudong Wang;Chen Wang;Yuxin Song;Miao Zhang;Z. Xue;Shumin Wang;Zhongyunshen Zhu
中科院分区：
文献类型：
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作者：
Yuekun Yang;Xudong Wang;Chen Wang;Yuxin Song;Miao Zhang;Z. Xue;Shumin Wang;Zhongyunshen Zhu
GeSn提供比Ge减小的带隙，并且已经用于具有扩展截止波长的Si基红外光电探测器。然而，传统的GeSn/Ge异质结构通常包含缺陷，如失配位错，由于晶格失配问题。在体材料GeSn/Ge异质结上制作的光电探测器中，大尺寸缺陷会引起较大的暗电流。在这里，我们展示了一个灵活的GeSn/Ge双纳米线（NW）的结构，其中的应变弛豫是通过弹性变形而不引入缺陷和特征尺寸自然是在纳米级。具有低暗电流的光电探测器可以构建在GeSn/Ge双NW上，与Ge NW相比，它具有超过2 μm的扩展探测波长和更高的响应度。此外，铁电聚合物侧栅的耗尽效应可以进一步抑制暗电流。我们的工作表明，灵活的GeSn/Ge双NW可能会打开一条途径，硅兼容的光电电路在短波长红外范围内工作。
GeSn offers a reduced bandgap than Ge and has been utilized in Si-based infrared photodetectors with extended cutoff wavelength. However, traditional GeSn/Ge heterostructure usually consists defects like misfit dislocations due to the lattice mismatch issue. The defects with the large feature size of photodetector fabricated on bulk GeSn/Ge heterostructure induces considerable dark current. Here, we demonstrate a flexible GeSn/Ge dual-nanowire (NW) structure, in which the strain relaxation is achieved by the elastic deformation without introducing defects and the feature dimension is naturally at nanoscale. Photodetector with low dark current can be built on GeSn/Ge dual-NW, which exhibits an extended detection wavelength beyond 2 μm and the enhanced responsivity compared to Ge NW. Moreover, the dark current can be further suppressed by the depletion effect from ferroelectric polymer side gate. Our work suggests the flexible GeSn/Ge dual-NW may open an avenue for Si-compatible optoelectronic circuits operating in the short-wavelength infrared range.