High-performance Ge-on-insulator lateral p-i-n waveguide photodetectors for electronic–photonic integrated circuits at telecommunication wavelengths

• Main Authors: Huang, Tzu-Yang, Bansal, Radhika, Ghosh, Soumava, Lee, Kwang Hong, Chen, Qimiao, Tan, Chuan Seng, Chang, Guo-En
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2024
• Subjects: Engineering; Ge; Photoresistor
• Online Access: https://hdl.handle.net/10356/173591
• Institution: Nanyang Technological University

We report high-performance germanium-on-insulator (GeOI) waveguide photodetectors (WGPDs) for electronic– photonic integrated circuits (EPICs) operating at telecommunication wavelengths. The GeOI samples were fabricated using layer transfer and wafer-bonding techniques, and a high-quality Ge active layer was achieved. Planar lateral p-i-n WGPDs were fabricated and characterized, and they exhibited a low dark current of 0.1 μA. Strain-induced alterations in the optical properties were observed, resulting in an extended photodetection range up to λ =1638 nm. This range encompasses crucial telecommunication bands. The WGPDs exhibited a high responsivity of 0.56A/W and a high detectivity of D∗ = 1.87 × 109cmHz1/2W- 1 at 1550 nm. A frequencyresponse analysis revealed that increasing the bias voltage from −1 to −9V enhances the 3-dB bandwidth from 31 to 49 MHz. This study offers a comprehensive understanding of GeOI WGPDs, fostering high-performance EPICs with implications for telecommunications and beyond.