Near-perfect light absorbers (NPLAs), with absorbance, A , of at least 99%, have a wide range of applications ranging from energy and sensing devices to stealth technologies and secure communications. Previous work on NPLAs has mainly relied upon plasmonic structures or patterned metasurfaces, which require complex nanolithography, limiting their practical applications, particularly for large-area platforms. Here, we use the exceptional band nesting effect in TMDs, combined with a Salisbury screen geometry, to demonstrate NPLAs using only two or three uniform atomic layers of transition metal dichalcogenides (TMDs). The key innovation in our design, verified using theoretical calculations, is to stack monolayer TMDs in such a way as to minimize their interlayer coupling, thus preserving their strong band nesting properties. We experimentally demonstrate two feasible routes to controlling the interlayer coupling: twisted TMD bi-layers and TMD/buffer layer/TMD tri-layer heterostructures. Using these approaches, we demonstrate room-temperature values of A =95% at λ=2.8 eV with theoretically predicted values as high as 99%. Moreover, the chemical variety of TMDs allows us to design NPLAs covering the entire visible range, paving the way for efficient atomically-thin optoelectronics.
Bibliographical noteFunding Information:
This work was primarily supported by the National Science Foundation (NSF) through the DMREF program under Award No. DMR-1921629 and DMR-1921818, and in part by the NSF under Award No. ECCS-1542202. Portions of this work were conducted in the Minnesota Nano Center, which is supported by the NSF through the National Nanotechnology Coordinated Infrastructure (NNCI) under Award No. ECCS-2025124. S.L. is also supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2021R1A6A3A14038837). M.S.J. acknowledges the support by the NRF grant funded by the Korea government (MSIT) (2022R1A2C2092095). M.S.J. and T.L. thank Sangjun Han for his contribution to calculating the optical absorption in 2D material-based Salisbury screens. D.S. and S.J.K. thank Sang-Hyun Oh for use of the optical setup used in this work.
© 2023, The Author(s).
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