Mechanically flexible mid-wave infrared imagers using black phosphorus ink films

Area of Science:

• Materials Science
• Optoelectronics
• Nanotechnology

Background:

• Mid-wave infrared (MWIR) sensing is crucial for applications like bioimaging and autonomous navigation.
• Current MWIR photodetectors are rigid, limiting their use in flexible and conformable systems.
• Black phosphorus (BP) van der Waals (vdW) materials offer high sensitivity and solution-processability for flexible electronics.

Purpose of the Study:

• To develop mechanically flexible MWIR imagers.
• To utilize black phosphorus (BP) ink for fabricating flexible photodetectors.
• To demonstrate the robustness and imaging capabilities of these flexible MWIR devices.

Main Methods:

• Fabrication of MWIR photodiodes on thin plastic substrates using BP ink films.
• Mechanical testing of photodetector responsivity under various bending radii and cycles.
• Evaluation of imaging performance with directional light sources.

Main Results:

• Demonstrated mechanically robust responsivity in flexible BP photodiodes down to 2.5-mm bending radii.
• Maintained device performance after 5000 bending cycles, indicating high durability.
• Achieved precise full-azimuthal imaging capabilities, showcasing the practical utility of flexible MWIR sensors.

Conclusions:

• Presented a scalable method for fabricating large-area, flexible MWIR imaging devices.
• Established the potential of BP ink films for robust, conformable MWIR sensing.
• Paved the way for integrating flexible MWIR imagers with other flexible electronic systems.