[TuP3D] D. Photonic devices and related technologies

2:00 PM - 4:00 PM JST(5:00 AM - 7:00 AM UTC)

[TuP3D-18 LN] High-Frequency Modulation Characteristics of 625-nm AlGaInP Micro-LEDs Grown on GaAs for Optical Interconnect Applications

〇Chee Keong Yee¹, Zhi-An Lin¹, Ming-June Wu², Natchanon Prechatavanich², Cheng-En Wu¹, Zi-Wei Chye³, Chao-Hsin Wu^1,2,3,4 (1. National Taiwan Univ., Graduate Inst. of Photonics and Optoelectronics (Taiwan), 2. National Taiwan Univ., Graduate School of Advanced Tech. (Taiwan), 3. National Taiwan Univ., Graduate Inst. of Electronics Engineering (Taiwan), 4. National Taiwan Univ., Center for Quantum Sci. and Engineering (Taiwan))

This work investigates the high-frequency modulation performance of 625-nm AlGaInP red micro-LEDs grown on GaAs substrates for optical interconnect and visible light communication applications. Micro-LED devices with mesa sizes of 13×20 µm², 26×40 µm², and 39×60 µm² were fabricated using AlGaInP multiple quantum well structures. Sidewall passivation and RF-compatible metal contacts were implemented to improve device performance and enable high-speed measurements. Electrical characterization shows clear diode behavior with turn-on voltages between 2.2 and 2.5 V and low leakage current. Optical measurements reveal a quasi-linear relationship between output power and current density, indicating stable radiative recombination. Larger devices exhibit higher optical power and improved peak external quantum efficiency due to reduced perimeter recombination effects. In contrast, smaller devices sustain higher current density and demonstrate superior modulation performance. The smallest device (13×20 µm²) achieves a −3 dB modulation bandwidth exceeding 30 MHz, attributed to reduced junction capacitance and shorter carrier lifetime. These results highlight the importance of device scaling in optimizing both efficiency and modulation speed, demonstrating the potential of AlGaInP micro-LEDs as high-speed visible light sources for optical communication systems.