Flexible broadband WS2/Si optical position-sensitive detector with high sensitivity and fast speed

• Published in: International journal of minerals, metallurgy and materials metallurgy and materials, 2023-06, Vol.30 (6), p.1217-1224
• Main Authors: Liu, Yunjie, Wu, Yupeng, Guo, Fuhai, Liu, Yingming, Zhao, Shirong, Li, Siqi, Yu, Weizhuo, Hao, Lanzhong
• Format: Article
• Language: English
• Subjects: Broadband; Ceramics; Characterization and Evaluation of Materials; Chemistry and Materials Science; Composites; Corrosion and Coatings; Crystals; Electromagnetic absorption; Etching; Flexibility; Fragility; Glass; Heterostructures; Materials Science; Metallic Materials; Natural Materials; Optics; Position sensing; Rigidity; Sensitivity; Sensors; Spectral sensitivity; Surfaces and Interfaces; Thin Films; Tribology
• ISSN: 1674-4799; 1869-103X
• DOI: 10.1007/s12613-023-2600-2

Si-based optical position-sensitive detectors (PSDs) have stimulated the interest of researchers due to their wide range of practical applications. However, due to the rigidity and fragility of Si crystals, the applications of flexible PSDs have been limited. Therefore, we presented a flexible broadband PSD based on a WS 2 /Si heterostructure for the first time. A scalable sputtering method was used to deposit WS 2 thin films onto the etched ultrathin crystalline Si surface. The fabricated flexible PSD device has a broad spectral response in the wavelength range of 450–1350 nm, with a high position sensitivity of ∼539.8 mV·mm −1 and a fast response of 2.3 µs, thanks to the strong light absorption, the built-in electrical field at the WS 2 /Si interface, and facilitated transport. Furthermore, mechanical-bending tests revealed that after 200 mechanical-bending cycles, the WS 2 /Si PSDs have excellent mechanical flexibility, stability, and durability, demonstrating the great potential in wearable PSDs with competitive performance.