A CMOS Luminescence Intensity and Lifetime Dual Sensor Based on Multicycle Charge Modulation

Area of Science:

• Photonics and Optoelectronics
• Materials Science
• Sensor Technology

Background:

• Luminescence is crucial for scientific and industrial applications.
• Existing sensors may lack sensitivity or compatibility with advanced manufacturing processes.
• Accurate luminescence intensity and lifetime measurements are vital for various sensing tasks.

Purpose of the Study:

• To develop a novel complementary metal-oxide-semiconductor (CMOS) sensor chip capable of simultaneous luminescence intensity and lifetime sensing.
• To enhance sensitivity for low-light conditions using a parasitic insensitive multicycle charge modulation scheme.
• To demonstrate the sensor's utility in measuring material properties and environmental parameters.

Main Methods:

• Design and implementation of an in-pixel capacitive transimpedance amplifier (CTIA) based structure for charge accumulation.
• Utilization of a pinned photodiode with low dark current for luminescence detection.
• Development of a parasitic insensitive multicycle charge modulation scheme for high-sensitivity lifetime extraction.

Main Results:

• Achieved responsivity of 2.1-mV/(nW/cm²) and resolution of 4.38-nW/cm² at 630 nm for intensity measurement.
• Demonstrated a lifetime measurement resolution of 45 ns.
• Successfully measured luminescence lifetimes of InGaN-based LEDs and an oxygen-sensitive chromophore, showing high sensitivity to oxygen concentration.
• Validated the CMOS sensor for water quality testing.

Conclusions:

• The proposed CMOS sensor chip effectively integrates luminescence intensity and lifetime sensing with high sensitivity.
• The parasitic insensitive multicycle charge modulation scheme enhances low-light lifetime extraction.
• The sensor demonstrates significant potential for applications in material characterization, oxygen sensing, and environmental monitoring.