Organic-on-silicon complementary metal-oxide-semiconductor colour image sensors

Area of Science:

• Materials Science
• Electrical Engineering
• Optoelectronics

Background:

• Complementary metal-oxide-semiconductor (CMOS) image sensors are crucial for light detection.
• Reducing pixel size for high resolution in CMOS sensors decreases photon capture and sensitivity.
• Current silicon-based technology faces limitations in sensitivity at sub-micron pixel scales.

Purpose of the Study:

• To enhance the sensitivity and resolution of CMOS color image sensors.
• To overcome the limitations of reduced pixel sizes in high-resolution imaging.
• To develop a novel hybrid sensor architecture combining organic and silicon technologies.

Main Methods:

• Superposing organic photodiodes (OPDs) onto existing CMOS circuits with silicon photodiodes.
• Developing novel organic semiconductor materials with green light absorption properties.
• Fabricating highly efficient green-light-sensitive OPDs without color filters.
• Designing a new silicon-based CMOS circuit incorporating blue and red color filters.

Main Results:

• A novel organic-on-silicon hybrid image sensor architecture was successfully fabricated.
• The hybrid design effectively doubles the light-input surface area per pixel.
• Highly efficient green-light-sensitive OPDs were developed, eliminating the need for green color filters.
• The hybrid sensor demonstrated its capability by capturing a full-color image.

Conclusions:

• The developed organic-on-silicon hybrid CMOS color image sensor significantly improves sensitivity and resolution.
• This technology offers a promising solution for next-generation high-performance image sensors.
• The integration of selective organic photodiodes with CMOS circuits represents a significant advancement in imaging technology.