Inorganic Semiconductor-Based Flexible UV Photodetector Arrays Achieved by Specific Flip-Chip Bonding

Area of Science:

• Materials Science
• Optoelectronics
• Semiconductor Physics

Background:

• Flexible ultraviolet photodetectors (UV-PDs) are crucial for applications requiring environmental adaptability and wearability.
• Inorganic semiconductors offer excellent optoelectronic properties and mechanical stability but face challenges in flexible device fabrication due to high processing temperatures and brittleness.
• Existing methods struggle to integrate high-quality inorganic semiconductors into flexible optoelectronic devices.

Purpose of the Study:

• To develop a fabrication technique for high-performance flexible UV photodetector arrays (UV-FPDAs) using inorganic semiconductors.
• To overcome the limitations of high-temperature processing and material brittleness in flexible optoelectronics.
• To demonstrate the imaging capabilities of the fabricated flexible UV-PD array.

Main Methods:

• A specific flip-chip bonding fabrication technique was developed to utilize high-temperature treated inorganic semiconductor materials.
• A 7 × 7 pixel flexible UV photodetector array (UV-FPDA) device was constructed using a vertical architecture Mg-doped ZnO/NiO (Mg:ZnO/NiO) heterojunction transistor.
• An artificial neural network was employed to process the photoresponse characteristics of each pixel for UV light information imaging.

Main Results:

• The fabricated UV-FPDAs achieved a high responsivity of 75.8 A/W and an outstanding detectivity of 8.5 × 10¹² Jones.
• The devices exhibited excellent mechanical bending stability, crucial for flexible applications.
• Clear imaging of UV light information was successfully demonstrated through artificial neural network analysis of pixel data.

Conclusions:

• The developed flip-chip bonding technique enables the integration of high-performance inorganic semiconductors into flexible UV photodetection devices.
• The Mg-doped ZnO/NiO heterojunction transistors demonstrate significant potential for high-performance flexible UV detection.
• This work presents a promising pathway for advancing inorganic semiconductor applications in flexible optoelectronics and UV imaging.