Oxygen intercalation in 2D layered PtSe2 for tunable bandgap infrared photoelectric materials

Abstract

Infrared materials play a pivotal role in driving societal advancement across various domains. Bilayer PtSe2 with bandgap of 0.2 eV is an ideal material for infrared applications. However, the inherent limitation of the untunable bandgap in bilayer PtSe2 restricts its utility, particularly in the context of state-of-the-art two-color infrared detectors. Therefore, by introduction of quantum confinement effect, PtSe2[O]y superlattice was constructed via intercalating O atoms into interlayer space of PtSe2, and kinetic stability was confirmed by ab initio molecular dynamics. Considering van der Waals interactions of interlayer, PtSe2[O]y superlattice can be exfoliated into few-layer PtSe2[O]y. By employing density functional theory, optical and electrical properties of PtSe2[O]y superlattice and few-layer PtSe2[O]y were calculated. Tunable bandgaps were achieved by manipulating the O composition y, ranging from 0 eV to 0.21 eV (covering wavelengths > 5.9 μm) for the PtSe2[O]y superlattice and from 1.12 eV to 0.15 eV (covering wavelengths from 1.1 μm to 8.3 μm) for monolayer PtSe2[O]y. Considering the continuously tunable bandgap covering from near-infrared to mid-infrared absorption spectrum, PtSe2[O]y could be a promising candidate with a wide-application in the field of infrared photoelectric materials.