Multilayered PtSe2/pyramid-Si heterostructure array with light confinement effect for high-performance photodetection, image sensing and light trajectory tracking applications

Abstract

Two-dimensional layered (2D) materials are currently attracting intensive research interest for high-performance photodetection and other optoelectronic applications. However, the study of device integration for multifunctional optoelectronic applications is still at a nascent stage. Here, the assembly of a multilayered PtSe₂/pyramid-Si heterostructure-based photodetector array consisting of 8 × 8 device units is demonstrated. Owing to the pronounced light confinement effect of the heterostructures, the devices present an prominent photovoltaic effect, which enables efficient self-driven photodetection in a broadband wavelength spectrum. The I_light/I_dark ratio, responsivity, external quantum efficiency (EQE) and specific detectivity can attain values as high as 5.51 × 10⁶, 567 mA W⁻¹, 87% and 1.26 × 10¹³ jones, respectively, upon 810 nm near-infrared (NIR) light illumination. What is more, benefiting from the large-scale homogeneous material growth technique, the photodetector array exhibits excellent uniformity and repeatability in photoresponse performance with negligible unit-to-unit variation. The above characteristics provide the photodetector array with the capability of recording a simple image produced by NIR illumination and monitoring a moving photonic signal, showing the great possibility for NIR image sensing and light trajectory tracking applications.