Adam Alfieri1,Michael Motala2,Michael Snure3,Jason Lynch1,Pawan Kumar1,Huiqin Zhang1,Susanna Post4,Christopher Muratore4,Joshua Hendrickson3,Nicholas Glavin3,Deep Jariwala1
University of Pennsylvania1,UES, Inc.2,Air Force Research Laboratory3,University of Dayton4
Adam Alfieri1,Michael Motala2,Michael Snure3,Jason Lynch1,Pawan Kumar1,Huiqin Zhang1,Susanna Post4,Christopher Muratore4,Joshua Hendrickson3,Nicholas Glavin3,Deep Jariwala1
University of Pennsylvania1,UES, Inc.2,Air Force Research Laboratory3,University of Dayton4
Platinum diselenide (PtSe<sub>2</sub>) is a novel van der Waals semimetal that exhibits extraordinarily strong interaction with light (a refractive index that exceeds 4 and an extinction coefficient over 2) over a broadband range from the visible to near infrared (NIR). We demonstrate cm-scale growth of 18 nm thick PtSe<sub>2</sub> layers with a solar-weighted absorption of 87.6% (from 400 nm – 900 nm) when transferred onto a 40 nm Al<sub>2</sub>O<sub>3</sub>/Ag reflector substrate<sup>[1]</sup>. By patterning the PtSe<sub>2</sub> layer into a periodic array of nanoresonators, the electric field can be localized in the PtSe<sub>2</sub>, resulting in an average visible range absorption of 97.9% and a solar-weighted absorption of 97.0% (400 nm to 900 nm) in a total structure thickness of 158 nm and an active layer thickness of only 18 nm. Our PtSe<sub>2</sub> metasurfaces present a scalable approach to ultrathin broadband absorbers for photodetection and solar energy harvesting.<br/><br/>Reference:<br/>1. A.D. Alfieri, M.J. Motala, M. Snure, J. Lynch, P. Kumar, H. Zhang, S. Post, C. Muratore, J.R. Hendrickson, N.R. Glavin, D. Jariwala. arXiv.2208.13269, 2022.