High-performance broadband heterojunction photodetectors based on multilayered PtSe directly grown on a Si substrate

• Published in: Nanoscale 2018-08, Vol.1 (32), p.15285-15293
• Main Authors: Xie, Chao, Zeng, Longhui, Zhang, Zhixiang, Tsang, Yuen-Hong, Luo, Linbao, Lee, Jung-Ho
• Format: Article
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/c8nr04004d

Two-dimensional group-10 transition metal dichalcogenides have recently attracted increasing research interest because of their unique electronic and optoelectronic properties. Herein, we present vertical hybrid heterojunctions of multilayered PtSe 2 and Si, which take advantage of large-scale homogeneous PtSe 2 films grown directly on Si substrates. These heterojunctions show obvious rectifying behavior and a pronounced photovoltaic effect, enabling them to function as self-driven photodetectors operating at zero bias. The photodetectors can operate in both photovoltage and photocurrent modes, with responsivity values as high as 5.26 × 10 6 V W −1 and 520 mA W −1 at 808 nm, respectively. The I light / I dark ratio, specific detectivity, and response speed are 1.5 × 10 5 , 3.26 × 10 13 Jones, and 55.3/170.5 μs, respectively. Furthermore, the heterojunctions are highly sensitive in a broad spectral region ranging from deep ultraviolet to near-infrared (NIR) (200-1550 nm). Because of the strong NIR light absorption of PtSe 2 , the heterojunctions exhibit photocurrent responsivities of 33.25 and 0.57 mA W −1 at telecommunication wavelengths of 1310 and 1550 nm, respectively. Considering the excellent performance of the PtSe 2 /Si heterojunctions, they are highly suitable for application in high-performance broadband photodetectors. The generality of the above results also signifies that the proposed in situ synthesis method has great potential for future large-scale optoelectronic device integration. The broadband heterojunction photodetectors, exhibiting superior photoresponse performances ranged from deep ultraviolet to near-infrared, were made by growing a multilayered PtSe 2 film directly onto Si.