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Ambient-Light-Immune NIR Photodetector Based on WS2/SiHMs Heterojunction for Hypertension Taxonomy Via CNN
Yaqi Zhao1, Haolan Xu1, Xin Wang1
1School of Microelectronics, Micro Electromechanical System Research Center of Engineering and Technology of Anhui Province, Hefei University of Technology, Hefei, Anhui, 230009, P. R. China.
Advanced Healthcare Materials
|November 7, 2025
Summary
A novel ambient-light-immune photodetector using WS2/SiHM technology enables accurate blood pressure monitoring via photoplethysmography (PPG). This breakthrough improves hypertension assessment in wearable health devices.
Area of Science:
- Materials Science
- Biomedical Engineering
- Optoelectronics
Background:
- Hypertension is a leading global cause of death and disease.
- Accurate blood pressure (BP) monitoring via photoplethysmography (PPG) is challenging due to ambient light interference.
- Existing PPG techniques struggle with reliable data acquisition in daily life settings.
Purpose of the Study:
- To develop an ambient-light-immune photodetector for high-fidelity PPG waveform acquisition.
- To overcome the limitations of current PPG-based BP monitoring systems.
- To enable robust, non-invasive cardiovascular assessment for hypertension risk evaluation.
Main Methods:
- Fabrication of an in situ WS2/Si hexagonal micro-holes (WS2/SiHM) heterojunction photodetector using pulsed laser deposition (PLD).
- Leveraging the metallic phase characteristics of PLD-1T-WS2 for enhanced phot performance.
- Integration with a custom circuit and a convolutional neural network for data analysis.
Main Results:
- The WS2/SiHM heterojunction demonstrated a broad near-infrared (NIR) spectral response (700-1550 nm) with excellent visible-light rejection (>10^3).
- The device enabled robust PPG waveform acquisition under challenging ambient light conditions, outperforming commercial silicon photodiodes.
- The integrated system achieved over 90% accuracy in hypertension classification when combined with a convolutional neural network.
Conclusions:
- The developed WS2/SiHM photodetector offers a viable solution for ambient-light-immune PPG sensing.
- This technology presents a new paradigm for wearable health monitoring, particularly for continuous, non-invasive cardiovascular assessment.
- The system shows significant promise for accurate hypertension risk assessment and management.
