Zhu Xiaotian, Lin Fengyuan, Zhang Zhihong, Chen Xue, Huang Hao, Wang Dengkui, Tang Jilong, Fang Xuan, Fang Dan, Ho Johnny C, Liao Lei, Wei Zhipeng
State Key Laboratory of High Power Semiconductor Lasers, Changchun University of Science and Technology, Changchun 130022, China.
Department of Physics and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan 430072, China.
Nano Lett. 2020 Apr 8;20(4):2654-2659. doi: 10.1021/acs.nanolett.0c00232. Epub 2020 Mar 5.
Here, we design and engineer an axially asymmetric GaAs/AlGaAs/GaAs (G/A/G) nanowire (NW) photodetector that operates efficiently at room temperature. Based on the I-type band structure, the device can realize a two-dimensional electron-hole tube (2DEHT) structure for the substantial performance enhancement. The 2DEHT is observed to form at the interface on both sides of GaAs/AlGaAs barriers, which constructs effective pathways for both electron and hole transport in reducing the photocarrier recombination and enhancing the device photocurrent. In particular, the G/A/G NW photodetector exhibits a responsivity of 0.57 A/W and a detectivity of 1.83 × 10 Jones, which are about 7 times higher than those of the pure GaAs NW device. The recombination probability has also been significantly suppressed from 81.8% to 13.2% with the utilization of the 2DEHT structure. All of these can evidently demonstrate the importance of the appropriate band structure design to promote photocarrier generation, separation, and collection for high-performance optoelectronic devices.
在此，我们设计并制造了一种轴向不对称的 GaAs/AlGaAs/GaAs（G/A/G）纳米线（NW）光电探测器，其在室温下能高效运行。基于 I 型能带结构，该器件可实现二维电子 - 空穴管（2DEHT）结构以大幅提升性能。观察到 2DEHT 在 GaAs/AlGaAs 势垒两侧的界面处形成，这为电子和空穴传输构建了有效路径，从而减少光载流子复合并增强器件光电流。特别是，G/A/G NW 光电探测器表现出 0.57 A/W 的响应度和 1.83×10琼斯的探测率，这比纯 GaAs NW 器件高出约 7 倍。利用 2DEHT 结构后，复合概率也从 81.8%显著抑制至 13.2%。所有这些都能明显证明合适的能带结构设计对于促进光载流子产生、分离和收集以实现高性能光电器件的重要性。
