Interface Engineering via Photopolymerization-Induced Phase Separation for Flexible UV-Responsive Phototransistors

Area of Science:

• Materials Science
• Organic Electronics
• Photochemistry

Background:

• Interface engineering is crucial for optoelectronic device performance, enabling efficient charge separation and transport.
• Current methods for precise interface control are challenging and limited.
• Developing novel strategies for controlled heterojunction formation is essential for advancing optoelectronics.

Purpose of the Study:

• To introduce a facile and versatile protocol for constructing heterojunction semiconductor interfaces.
• To demonstrate the effectiveness of in situ thiol-ene click photopolymerization-induced phase separation for interface engineering.
• To achieve enhanced device performance in optoelectronic applications, specifically UV-responsive phototransistors.

Main Methods:

• Implementation of in situ thiol-ene click photopolymerization-induced phase separation.
• Fabrication of continuous mountainlike heterojunction interfaces.
• Utilizing a low-temperature photopolymerization paradigm adaptable to rigid and flexible substrates.
• Conducting control experiments with ex situ photopolymerization and in situ thermal polymerization.

Main Results:

• The developed protocol successfully generated continuous mountainlike heterojunction interfaces.
• These interfaces promote efficient exciton dissociation and facilitate hole transport.
• High-performance UV-responsive phototransistors were fabricated with a normalized detectivity up to 6.3 × 10¹⁴ cm Hz^1/2 W^-1.
• The in situ photopolymerization method demonstrated superiority over ex situ and thermal polymerization techniques.

Conclusions:

• In situ thiol-ene click photopolymerization-induced phase separation offers a facile and effective approach for creating advanced heterojunction interfaces.
• This method significantly enhances charge dynamics and device performance in optoelectronics.
• The low-temperature, adaptable paradigm holds promise for developing next-generation flexible and high-performance UV photodetectors.