Si-CMOS-compatible 2D PtSe2-based self-driven photodetector with ultrahigh responsivity and specific detectivity

Photodetectors (PDs) based on two-dimensional (2D) materials are attracting considerable research interest due to the unique properties of 2D materials and their tunable spectral response. However, their performance is not outstanding enough, and the compatibility of their fabrication process with Si-complementary metal oxide semiconductor (CMOS) process flow needs evaluation. Here, we report an unprecedented high-performance, air-stable, self-driven, and broadband room-temperature PD based on the architecture of the PtSe2/ultrathin SiO2/Si heterojunction. The PD exhibits a very prominent responsivity of 8.06 A W-1, a truly high specific detectivity of 4.78 x 10(13) cm Hz(1/2) W-1, an extremely low dark current of 0.12 pA, and a fantastic photocurrent/dark current ratio of 1.29 x 10(9) at zero bias. The measured photo-current responsivities at wavelengths of 375, 532, 1342, and 1550 nm are 2.12, 5.56, 18.12, and 0.65 mA W-1, respectively. Moreover, the fabricated 9 x 9 device array not only illustrates the very high uniformity and reproducibility of the PDs but also shows great potential in the field of ultraviolet-visible-near infrared illumination imaging applications with a fabrication fully compatible with Si-CMOS technologies. Our design of the PtSe2/ultrathin SiO2/Si heterojunction PD greatly suppresses dark current, improves the diode ideality factor, and increases the potential barrier. Accordingly, it paves the way for a general strategy to enhance the performance of PDs used in novel optoelectronic applications.

Automated summary

Photodetectors based on 2D materials have unique properties and tunable spectral response, but their performance and compatibility with Si-CMOS process flow need evaluation. This study presents a high-performance, stable, self-driven, and broadband room-temperature photodetector based on PtSe2/ultrathin SiO2/Si heterojunction, showing great potential in novel optoelectronic applications.