Long-Wave Infrared Photodetectors Based on 2D Platinum Diselenide atop Optical Cavity Substrates

Long-wave infrared (LWIR) photodetection is of high technological importance, having a wide range of applications that include thermal imaging and spectroscopy. Two-dimensional (2D) noble-transition-metal dichalcogenides, platinum diselenide (PtSe2) in particular, have recently shown great promise for infrared detection. However, previous studies have mainly focused on wavelengths up to the short-wave infrared region. In this work, we demonstrate LWIR photo-detectors based on multilayer PtSe2. In addition, we present an optical cavity substrate that enhances the light-matter interaction in 2D materials and thus their photodetection performance in the LWIR spectral region. The PtSe2 photoconductors fabricated on the TiO2/Au optical cavity substrate exhibit responsivities up to 54 mA/W to LWIR illumination at a wavelength of 8.35 mu m. Moreover, these devices show a fast photoresponse with a time constant of 54 ns to white light illumination. The findings of this study reveal the potential of multilayer PtSe2 for fast and broadband photodetection from visible to LWIR wavelengths.

Automated summary

This study demonstrates long-wave infrared (LWIR) photodetectors based on multilayer PtSe2, which show high responsivities and fast response characteristics at LWIR wavelengths. The design of an optical cavity substrate enhances the light-matter interaction in 2D materials, improving their photodetection performance in the LWIR spectral region.