Robust Piezo-Phototronic Effect in Multilayer γ-InSe for High-Performance Self-Powered Flexible Photodetectors
Robust Piezo-Phototronic Effect in Multilayer γ-InSe for High-Performance Self-Powered Flexible Photodetectors
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DOI：
10.1021/acsnano.9b03278
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发表时间：
2019-06-01
期刊：
影响因子：
17.1
通讯作者：
Hu, PingAn
中科院分区：
文献类型：
--
作者：
Dai, Mingjin;Chen, Hongyu;Hu, PingAn
压电光电效应是提高二维半导体光电器件性能的有效手段。然而，目前报道的单层2D半导体不被认为是适合实际的灵活的压电光电探测器，由于其不足的光吸收和机械耐用性，虽然它们具有很强的压电性。在这项工作中，我们证明，不同于2 H相过渡金属二硫属化物，γ相的铟硒具有六角晶胞具有破反转对称性的所有层数，并具有很强的二次谐波产生效果。在此基础上，提出了一种基于多层膜γ-InSe的柔性自供电光电探测器，该探测器在压电光电效应的驱动下，无需任何能量供给即可工作。该器件在400 nm光照下的光子响应率为824 mA/W（0.368 mW/cm（2））。此外，该光电探测器的响应度和响应速度进一步提高了高达696%和1010%，分别当施加0.62%的单轴拉伸应变。我们的设备在6个月的测试时间内表现出高可靠性和稳定性。这些重要的发现为基于多层二维半导体构建高性能柔性压电光电探测器提供了一条有前途的途径。
The piezo-phototronic effect has been promising as an effective means to improve the performance of two-dimensional (2D) semiconductor based optoelectronic devices. However, the current reported monolayer 2D semiconductors are not regarded as suitable for actual flexible piezotronic photodetectors due to their insufficient optical absorption and mechanical durability, although they possess strong piezoelectricity. In this work, we demonstrate that, unlike 2H-phase transition-metal dichalcogenides, gamma-phase InSe with a hexagonal unit cell possesses broken inversion symmetry in all the layer numbers and has a strong second-harmonic generation effect. Moreover, driven by the piezo-phototronic effect, a flexible self-powered photodetector based on multilayer gamma-InSe, which can work without any energy supply, is proposed. The device exhibited ultrahigh photon responsivity of 824 mA/W under light illuminations of 400 nm (0.368 mW/cm(2)). Moreover, the responsivity and response speed of this photodetector were enhanced further by as much as 696% and 1010%, respectively, when a 0.62% uniaxial tensile strain was applied. Our devices exhibit high reliability and stability during a 6 month test time. These significant findings offer a promising pathway to construct high-performance flexible piezo-phototronic photodetectors based on multilayer 2D semiconductors.