High-Barrier-Height Ti3C2Tx/Si Microstructure Schottky Junction-Based Self-Powered Photodetectors for Photoplethysmographic Monitoring

作者：Song, Longmei; Xu, Enze; Yu, Yongqiang^*; Jie, Jianyong; Xia, Yu; Chen, Shirong; Jiang, Yang; Xu, Gaobin; Li, Dachuang; Jie, Jiansheng^*

来源：Advanced Materials Technologies, 2022, 7(12): 2200555.

DOI：10.1002/admt.202200555

• blood pressure measurement
• heart-rate measurement
• MXene
• Schottky diode
• Si microstructure

A high Schottky barrier height (phi(B)) is one of the essential prerequisites for achieving high-performance self-powered Schottky-barrier diode (SBD)-based photodetector. The phi(B) value is predominantly determined by the metal function and interface quality of the metal/semiconductor contact. 2D MXenes with adjustable work functions and dangling bond-free properties are promising building blocks for constructing self-powered SBD with high phi(B). Herein, a novel Ti3C2Tx MXene/Si hexagonal microhole array (SiHMA) van der Waals SBD is developed for the first time via a feasible solution process. Significantly, the device possesses a large phi(B) up to approximate to 1.07 eV, which is among the highest for the Si-based SBD. In consequence, the Ti3C2Tx/SiHMA SBD yields a large responsivity up to 302 mA W-1 and detectivity as high as 5.4 x 10(13) Jones in a self-powered model, surpassing the performance of most 2D material/Si photodiodes reported to date. Furthermore, it is demonstrated that featured and reliable fingertip photoplethysmogram (PPG) signals can be detected using the self-powered SBD, enabling us to further accurately extract the heart rate (HR), and blood pressures (BP) using the PPG-only method. This work paves the way for the construction of high-performance MXenes-based self-powered SBDs for health monitoring.

• 单位
  苏州大学