Two-Dimensional Material-Enhanced Flexible and Self-Healable Photodetector for Large-Area Photodetection

Flexible photodetectors are fundamental elements to develop flexible/wearable systems, which can be widely used for in situ health and environmental monitoring, human-machine interacting, flexible displaying, etc. However, the degraded performance or even malfunction under severe mechanical deformation and/or damage remains a key challenge for current flexible photodetectors. In this article, a flexible photodetector is developed with strong self-healing capability and stable performance under large deformation. This photodetector is made of the 2D material self-healing film by mixing 2D materials homogenously with the self-healing polymer of imidazolium-based norbornene polymerized with ionic liquids and counterions. The 2D material self-healing films show enhanced light absorption, and thus, decent photoresponse as compared to the pure self-healing film. The achieved photoresponse remains stable and even increases under small tensile strain within 150%, while decreases slightly under large tensile strain up to 1000%. Moreover, the photodetector not only can be fully recovered from repeated mechanical cuttings, but also presents excellent long-term stability in ambient condition for 500 days without showing any obvious degraded performance. Furthermore, a large-area 2D material self-healing photodetection array is designed with adjustable pixel size, which successfully recognizes the patterns of T, J, and U.

Automated summary

A flexible photodetector with strong self-healing capability and stable performance under large deformation is developed in this article. The photodetector shows stable photoresponse and even increases under small tensile strain, with a large-area 2D material self-healing photodetection array designed for pattern recognition.