A High-Performance Optical Memory Array Based on Inhomogeneity of Organic Semiconductors

Area of Science:

• Organic electronics
• Materials science
• Optoelectronics

Background:

• Organic optical memory devices are crucial for optoelectronic applications.
• Existing memory transistors face challenges in fabrication complexity and cost.

Purpose of the Study:

• To develop flexible nonvolatile optical memory devices.
• To investigate charge trapping mechanisms in organic semiconductors for memory applications.

Main Methods:

• Fabrication of organic field-effect transistors using bis[1]benzothieno[2,3-d;2',3'-d']naphtho[2,3-b;6,7-b']dithiophene (BBTNDT).
• Inducing charge trapping centers via nanosprout inhomogeneity in organic thin films.
• Scaling up devices to a 16x16 active matrix array on a flexible substrate.

Main Results:

• Achieved high mobility (7.7 cm² V⁻¹ s⁻¹) and photoresponsivity (433 A W⁻¹).
• Demonstrated long retention time (>6 h) with a high current ratio (>10⁶).
• Successfully mapped 2D optical images using the flexible array with low operating voltage (<3 V).

Conclusions:

• BBTNDT-based transistors offer a facile and cost-effective alternative to standard floating gate memory transistors.
• BTBT derivatives show significant potential for high-performance optical memory transistors.
• Understanding charge trapping mechanisms related to nanosprouts is key for optimizing performance.