Phototunable and Photopatternable Polymer Semiconductors

Area of Science:

• Materials Science
• Organic Electronics
• Polymer Chemistry

Background:

• Rapid advancements in conjugated donor-acceptor (D-A) polymer semiconductors have led to high charge mobilities.
• Polymer semiconductors are integral to various devices like sensors, photodetectors, and artificial synapses.
• Stimuli-responsive and phototunable polymer semiconductors are gaining traction for enhanced device functionalities.

Purpose of the Study:

• To explore phototunable and photopatternable polymer semiconductors for advanced electronic applications.
• To demonstrate light-controlled tuning of semiconducting properties and device performance.
• To achieve precise patterning of polymer semiconductors for complex device fabrication.

Main Methods:

• Blending poly(diketopyrrolopyrrole-quaterthiophene) (PDPP4T) with hexaarylbiimidazole (HABI) for photo/thermal-responsive field-effect transistors (FETs).
• Incorporating photoswitchable groups (azo, spiropyran) into polymer side chains for phototunable charge transport.
• Utilizing a diazirine-based cross-linker (4CNN) and azide-functionalized polymers for photopatterning various semiconductor types.

Main Results:

• Blended films of PDPP4T:HABI enabled nonvolatile memory devices programmable by light and erasable by heat.
• Polymers with photoswitchable side chains exhibited reversible tuning of FET performance via UV/Vis or NIR light, with tristable states achieved using dual azo groups.
• Photopatterning of p-type, n-type, and ambipolar semiconductors was successful using 4CNN (≤3% loading) and azide-based photoresists, yielding uniform and solvent-resistant films.

Conclusions:

• Phototunable polymer semiconductors offer remote control over device characteristics using light stimuli.
• Photopatterning techniques enable precise fabrication of polymer semiconductor devices, including multilayer structures.
• These advancements facilitate the development of sophisticated, solution-processable electronic devices with tunable functionalities.