CC BY
3Broadband optical properties of anisotropic palladium diselenide
G. Ermolaev12, A. Slavich1, M. Tatmyshevskiy1, G. Tselikov1,2, N. Pak1*, D. Grudinin1, I. Kruglov1, A. Arsenin1'2
1- Center for Photonics and 2D Materials, Moscow Institute of Physics and Technology, Dolgoprudny, Russia 2- Emerging Technologies Research Center, XPANCEO, Dubai Investment Park First, Dubai, United Arab
Emirates
* pak. nv@phystech. edu
Noble metal dichalcogenides (NMDCs) are distinguished among other advanced materials because of their strong layer-dependence of optical properties and interlayer interaction [1,2]. A promising example of NMDCs is a high refractive index PdSe2. This material has practical application due to impressive physical properties [2-4]. PdSe2-based heterostructures can be applied to polarization resolved photodetectors, field effect transistors, infrared sensors [3,5]. To describe the optical phenomena, on which optoelectronic devices are based, one needs to know refractive index n and excitation coefficient k. Nevertheless, there are few works related to the experimental determination of fundamental optical constants of PdSe2 [2,6], infrared region has not been not studied yet.
In this paper, we investigated broadband optical properties of bulk PdSe2 over a wide range of wavelengths. We measured a refractive index and an extinction coefficient by imaging ellipsometry method. Then we extended optical constants dependency to the far-infrared region according to a theoretical model. To evaluate broadened results, we used experimental data obtained from micro-reflectance and scattering near-field optical microscopy and density functional theory computations. Optical constants obtained in our work are necessary in optics and optoelectronics.
[1] W. Nishiyama, T. Nishimura, K. Ueno, et al, Quantitative determination of contradictory bandgap values of bulk PdSe2 from electrical transport properties, Adv. Funct. Mater., Vol. 32, No. 2108061 (2021).
[2] M.Y. Wei, Y. Zhang, C. Wang, et al, Layer-dependent optical and dielectric properties of centimeter-scale PdSe2 films grown by chemical vapor deposition, npj 2D Mater. Appl., Vol. 6, No. 1 (2022).
[3] M. Long, Y. Wang, P. Wang, et al, Palladium diselenide long-wavelength infrared photodetector with high sensitivity and stability, ACS Nano, Vol. 13(2), pp. 2511-2519, (2019).
[4] Y. Gu, H. Kai, J. Dong, et al, Two-dimensional palladium diselenide with strong in-plane optical anisotropy and high mobility grown by chemical vapor deposition, Adv. Mater., Vol. 32(19) No. 1906238 (2020).
[5] Y. Wang, J. Pang, Q. Cheng, et al, Applications of 2D-layered palladium diselenide and its van der Waals heterostructures in electronics and optoelectronics, Nano-Micro Let., Vol. 13, No. 143 (2021).
[6] G. Ermolaev, K. Voronin, D.G. Baranov, et al, Topological phase singularities in atomically thin high-refractive-index materials, Nat. Commun., Vol. 13, No. 2049 (2022).
