Light sensing in a photoresponsive, organic-based complementary inverter

Area of Science:

• Organic electronics
• Optoelectronics
• Materials science

Background:

• Organic complementary inverters are crucial for low-power electronic circuits.
• Developing photoresponsive organic circuits enables integration of sensing and logic functions.
• Organic thin-film transistors (OTFTs) offer flexibility and low-cost fabrication.

Purpose of the Study:

• To fabricate and characterize a photoresponsive organic complementary inverter.
• To investigate the light sensing capabilities of integrated p-type and n-type OTFTs.
• To demonstrate the control of circuit characteristics by light intensity and electrical bias.

Main Methods:

• Fabrication of an organic complementary inverter using p-channel pentacene and n-channel copper hexadecafluorophthalocyanine (F16CuPc) OTFTs.
• Integration of OTFTs with a polymeric gate dielectric.
• Characterization of device performance under varying light intensities and gate biases.

Main Results:

• The F16CuPc OTFT exhibited strong n-type photoresponse, while pentacene OTFT showed weaker p-type photoresponse.
• Circuit characteristics, including logic threshold voltage, were modulated by incident light intensity.
• Light sensing was successfully demonstrated using optical or combined optical/electrical signals.

Conclusions:

• The fabricated photoresponsive organic complementary inverter shows tunable electro-optical characteristics.
• The device's ability to sense light opens possibilities for optoelectronic applications.
• Potential applications include optical sensors, photodetectors, and electro-optical transceivers.