Graphene/PtSe<sub>2</sub>/Ultra-Thin SiO<sub>2</sub>/Si Broadband Photodetector with Large Responsivity and Fast Response Time
Burgeoning two-dimensional (2D) materials provide more opportunities to overcome the shortcomings of silicon-based photodetectors. However, the inevitable carrier loss in the 2D material/Si heterojunction has seriously hindered further improvement in responsivity and detection speed. Here, we propos...
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| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-03-01
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| Series: | Nanomaterials |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2079-4991/15/7/519 |
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| Summary: | Burgeoning two-dimensional (2D) materials provide more opportunities to overcome the shortcomings of silicon-based photodetectors. However, the inevitable carrier loss in the 2D material/Si heterojunction has seriously hindered further improvement in responsivity and detection speed. Here, we propose a graphene/PtSe<sub>2</sub>/ultra-thin SiO<sub>2</sub>/Si photodetector (PD) with multiple optimization mechanisms. Due to the fact that photo-generated carriers can travel in the graphene plane toward the Au electrode, the introduction of a top graphene contact with low sheet resistance provides a carrier collection path in the vertical direction and further restricts the carrier recombination behavior at the lateral grain boundary of PtSe<sub>2</sub> film. The ultra-thin SiO<sub>2</sub> passivation layer reduces the defects at the PtSe<sub>2</sub>/Si heterojunction interface. As compared to the counterpart device without the graphene top contact, the responsivity, specific detectivity, and response speed of graphene/PtSe<sub>2</sub>/ultra-thin SiO<sub>2</sub>/Si PD under 808 nm illumination are improved to 0.572 A/W, 1.50 × 10<sup>11</sup> Jones, and 17.3/38.8 µs, respectively. The device can detect broad-spectrum optical signals as measured from 375 nm to 1550 nm under zero bias. The PD line array with 16-pixel units shows good near-infrared imaging ability at room temperature. Our study will provide guiding significance for how to improve the comprehensive properties of PDs based on 2D/Si heterostructure for practical applications. |
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| ISSN: | 2079-4991 |