MoTe<sub>2</sub> Photodetector for Integrated Lithium Niobate Photonics
The integration of a photodetector that converts optical signals into electrical signals is essential for scalable integrated lithium niobate photonics. Two-dimensional materials provide a potential high-efficiency on-chip detection capability. Here, we demonstrate an efficient on-chip photodetector...
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| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-01-01
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| Series: | Nanomaterials |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2079-4991/15/1/72 |
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| Summary: | The integration of a photodetector that converts optical signals into electrical signals is essential for scalable integrated lithium niobate photonics. Two-dimensional materials provide a potential high-efficiency on-chip detection capability. Here, we demonstrate an efficient on-chip photodetector based on a few layers of MoTe<sub>2</sub> on a thin film lithium niobate waveguide and integrate it with a microresonator operating in an optical telecommunication band. The lithium-niobate-on-insulator waveguides and micro-ring resonator are fabricated using the femtosecond laser photolithography-assisted chemical–mechanical etching method. The lithium niobate waveguide-integrated MoTe<sub>2</sub> presents an absorption coefficient of 72% and a transmission loss of 0.27 dB µm<sup>−1</sup> at 1550 nm. The on-chip photodetector exhibits a responsivity of 1 mA W<sup>−1</sup> at a bias voltage of 20 V, a low dark current of 1.6 nA, and a photo–dark current ratio of 10<sup>8</sup> W<sup>−1</sup>. Due to effective waveguide coupling and interaction with MoTe<sub>2</sub>, the generated photocurrent is approximately 160 times higher than that of free-space light irradiation. Furthermore, we demonstrate a wavelength-selective photonic device by integrating the photodetector and micro-ring resonator with a quality factor of 10<sup>4</sup> on the same chip, suggesting potential applications in the field of on-chip spectrometers and biosensors. |
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| ISSN: | 2079-4991 |