Direct integration of micro-LEDs and a SPAD detector on a silicon CMOS chip for data communications and...

Area of Science:

• Optoelectronics
• Integrated Circuits
• Photonics

Background:

• Micro-light emitting diodes (micro-LEDs) offer potential for high-performance optical systems.
• Integration challenges have limited the widespread application of micro-LEDs in complex systems.
• Complementary Metal-Oxide-Semiconductor (CMOS) technology provides advanced driving and sensing capabilities.

Purpose of the Study:

• To demonstrate the direct integration of micro-LEDs onto a silicon CMOS drive chip.
• To develop a hybrid system capable of both optical communication and ranging.
• To evaluate the performance of the integrated micro-LED array and CMOS driver.

Main Methods:

• Utilized a transfer printing method for precise placement of singulated micron-sized light emitting diodes (micro-LEDs) onto a CMOS chip.
• Designed an 8x8 micro-LED device array with individual pixel control.
• Incorporated a Single Photon Avalanche Diode (SPAD) device within the CMOS driver for detection.

Main Results:

• Successfully integrated micro-LEDs onto a silicon CMOS drive chip.
• Demonstrated an 8x8 micro-LED array with modulation bandwidths up to 50 MHz.
• Achieved visible light communication data rates up to 1 Mbps.
• Showcased time-of-flight ranging with centimeter-scale resolution using the hybrid integrated system.

Conclusions:

• The hybrid integration of micro-LEDs and CMOS chips enables multifunctional optical systems on a single chip.
• This approach overcomes previous integration limitations, paving the way for advanced optoelectronic devices.
• The demonstrated system holds promise for applications in optical communications and high-resolution sensing.