Optical constants

Refractive index of PtSe₂ (Platinum diselenide)

Tharrault et al. 2025: 4L film; n,k 0.416–1.55 µm

Data: tabulated nk
Range: 0.416–1.55 µm
Points: 109
State: crystalline
Licence: CC0-1.0

Axis Log x Log y

Click the plot to set the calculator wavelength.

At one wavelength

Refractive index n: 4.52677
Extinction coefficient k: 2.96724

Permittivity ε₁: 11.6872
Permittivity ε₂: 26.864

Absorption coefficient α: 634571 cm⁻¹
Penetration depth δ = λ/(2πk): 31.5173 nm

Abbe number V_d: —
Chromatic dispersion dn/dλ: 0.213645 µm⁻¹

Group index n_g: 4.40123
Group velocity dispersion: — fs²/mm

Dispersion parameter D: — ps/(nm·km)
Photon energy: 2.11001 eV

ε = (n + ik)², α = 4πk/λ, n_g = n − λ dn/dλ, GVD = λ³/(2πc²) d²n/dλ², D = −(λ/c) d²n/dλ². Group-velocity dispersion is given for formula data only.

Use it in Lightsmith

Load this data in Python, simulate in one more line

pip install lightsmith

import lightsmith as ls

# PtSe2 (Platinum diselenide): Tharrault et al. 2025: 4L film; n,k 0.416–1.55 µm
ptse2 = ls.fetch_refractiveindex("main", "PtSe2", "Tharrault-4L", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(ptse2.range_nm)  # (416.05, 1550.38) nm
eps = ptse2.eps([633])  # complex permittivity

Downloads the original record once (pinned to the imported snapshot) and caches it.

import json, urllib.request
import lightsmith as ls

url = "https://materials.lightsmith.dev/v1/datasets/ds_852345059517/lightsmith"
ptse2 = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(ptse2.source)  # citation and provenance travel with the data

Any dataset here, as the library's Tabulated material (ptse2/tharrault-2025-4l).

# ... load ptse2 as above, then:
sim = ls.Simulation(
    particles=[ls.Particle(shape=ls.Sphere(radius_nm=50), material=ptse2)],
    medium_index=1.0,
    wavelengths=ls.WavelengthRange(start_nm=417, stop_nm=1000, num=81),
)
res = ls.solve(sim)  # exact Mie for a sphere
print(res.q_ext)     # extinction efficiency at each wavelength

Same spec runs with DDA, FDTD, BEM or T-matrix: ls.compare(sim, ["mie", "dda"]).

Materials guide Open a sphere of it in Studio Quick start Ask the community

Lightsmith is open source (MIT): Mie, T-matrix, BEM, DDA, FDTD, RCWA, TMM, mode solvers and inverse design behind one spec, on CPU or GPU. GitHub.

Comments and conditions

4L CVT-grown exfoliated crystal. The optical indexes are computed from the 2D surface conductivity using σ_2D·Z₀ = −2πi·(t/λ)·(ε_r−1), where Z₀ is the impedance of free space, i the imaginary unit, t the equivalent layered stack thickness and λ the free space wavelength. We use t = N_L t₀ with t₀ = 5.1 Å the single layer thickness. The measurement method accuratly determines Im{ε_r} = 2nk, but only Re{ε_r} = n² - k² as long as the optical absorption is non-zero.

References

M. Tharrault, S. Ayari, M. Arfaoui, E. Desgué, R. Le Goff, P. Morfin, J. Palomo, M. Rosticher, S. Jaziri, B, Plaçais,P. Legagneux, F. Carosella, C. Voisin, R. Ferreira, E. Baudin. Optical absorption in indirect semiconductor to semimetal PtSe₂ arises from direct transitions. Phys. Rev. Lett. 134, 066901 (2025) (Numerical data kindly provided by Marin Tharrault)

doi:10.1103/physrevlett.134.066901 Optical Absorption in Indirect Semiconductor to Semimetal <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow> <mml:msub> <mml:mrow> <mml:mi>PtSe</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> </mml:msub> </mml:mrow> </mml:math> Arises from Direct Transitions, Physical Review Letters (2025)

Cite

Marin Tharrault et al.. Optical Absorption in Indirect Semiconductor to Semimetal <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow> <mml:msub> <mml:mrow> <mml:mi>PtSe</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> </mml:msub> </mml:mrow> </mml:math> Arises from Direct Transitions. Physical Review Letters, 134, 066901 (2025), doi:10.1103/physrevlett.134.066901; Data from the refractiveindex.info database (M. N. Polyanskiy, Sci. Data 11, 94 (2024), doi:10.1038/s41597-023-02898-2)

Data

109 rows as published

CSV comma separated TXT tab separated YAML n, k Full database record original YAML All quantities CSV JSON metadata

PtSe2 (Platinum diselenide), Tharrault et al. 2025: 4L film; n,k 0.416–1.55 µm: n and k versus wavelength
λ (µm)	n	k
0.41605	4.13224	2.30274
0.41887	4.11479	2.34044
0.42171	4.11486	2.36312
0.4246	4.10303	2.39868
0.42753	4.09722	2.4337
0.4305	4.10786	2.45121
0.43351	4.13393	2.44706
0.43656	4.13253	2.47377
0.43966	4.10983	2.51551
0.4428	4.11969	2.53916
0.44599	4.11077	2.57525
0.44922	4.11078	2.59945
0.4525	4.11677	2.6116
0.45582	4.11999	2.62616
0.4592	4.12674	2.62045
0.46263	4.12757	2.63817
0.46611	4.12766	2.65486
0.46964	4.12286	2.67854
0.47322	4.12082	2.69987
0.47686	4.13487	2.71229
0.48056	4.15559	2.71202
0.48431	4.15827	2.73099
0.48813	4.16496	2.7499
0.492	4.18137	2.76131
0.49594	4.19293	2.77988
0.49994	4.23314	2.77245
0.504	4.23434	2.80302
0.50813	4.23732	2.8315
0.51233	4.26716	2.83353
0.5166	4.26776	2.86335
0.52094	4.31154	2.85243
0.52536	4.32299	2.87136
0.52985	4.35766	2.86859
0.53441	4.38187	2.87543
0.53906	4.38241	2.90632
0.54379	4.38422	2.9335
0.5486	4.42018	2.92909
0.5535	4.43664	2.93795
0.55849	4.44608	2.95519
0.56356	4.46357	2.95412
0.56873	4.48374	2.95296
0.574	4.52198	2.93035
0.57937	4.52524	2.94261
0.58483	4.52618	2.9622
0.5904	4.52737	2.97233
0.59608	4.53535	2.98435
0.60187	4.55699	3.04332
0.60777	4.58634	3.05556
0.61378	4.62068	3.05303
0.61992	4.62181	3.1027
0.62618	4.64613	3.13077
0.63257	4.66326	3.1675
0.63909	4.68953	3.1918
0.64575	4.73108	3.21164
0.65255	4.71842	3.2849
0.65949	4.79701	3.2499
0.66658	4.76777	3.31754
0.67383	4.83799	3.28808
0.68123	4.82243	3.35973
0.6888	4.85207	3.38407
0.69654	4.94025	3.36541
0.70446	5.00903	3.37063
0.71255	5.10586	3.3605
0.72084	5.19663	3.36022
0.72932	5.2841	3.3607
0.738	5.39777	3.31363
0.74689	5.48596	3.29168
0.756	5.55355	3.28596
0.76533	5.63233	3.24395
0.7749	5.75712	3.13612
0.78471	5.84876	3.0575
0.79477	5.89209	3.02342
0.80509	5.95386	2.93438
0.81569	6.00555	2.85256
0.82656	6.08619	2.72939
0.83773	6.10682	2.65686
0.84921	6.16473	2.54437
0.861	6.18665	2.45439
0.87313	6.20913	2.37133
0.8856	6.22821	2.27193
0.89844	6.26445	2.14495
0.91165	6.28896	2.04926
0.92526	6.32223	1.93132
0.93927	6.32707	1.82067
0.95372	6.4339	1.64741
0.96863	6.42249	1.52728
0.984	6.41777	1.40852
0.99987	6.37361	1.32121
1.01626	6.38547	1.21373
1.0332	6.36254	1.16429
1.06883	6.19337	0.95728
1.08758	6.27491	0.94993
1.107	6.23144	0.91958
1.12713	6.18576	0.88991
1.148	6.17218	0.83655
1.16966	6.18761	0.78311
1.19216	6.18046	0.76222
1.21553	6.14153	0.74689
1.24021	6.13075	0.71542
1.26553	6.10641	0.68087
1.29191	6.04791	0.6602
1.3194	6.00876	0.6311
1.34809	6.00136	0.60251
1.37806	6.0241	0.56236
1.40939	5.9715	0.513
1.44218	6.05053	0.40492
1.47653	6.09349	0.34123
1.51256	6.1211	0.28426
1.55038	6.26536	0.22095

Optical transmission calculator

Free-standing sample in vacuum, normal incidence

Transmittance T: —
Reflectance R: —

Fresnel reflection calculator

R_p: —
R_s: —
R = (R_p+R_s)/2: —
Phase φ_p: —
Phase φ_s: —
Brewster angle θ_B: —
Critical angle θ_C: —

PtSe₂ (Platinum diselenide): all datasets

About PtSe2 (Platinum diselenide)

Platinum diselenide (PtSe₂) is a member of the transition metal dichalcogenide (TMD) family, similar to materials like MoS₂ and WS₂. It forms layered structures that can be exfoliated into ultrathin layers or even monolayers. Unique among the TMDs, PtSe₂ has garnered attention due to its interesting electronic and optical properties. For instance, it exhibits both semiconducting and metallic behaviors depending on its layer thickness. Monolayer PtSe₂ possesses a direct bandgap, which is promising for applications in nanoelectronics and optoelectronics. Additionally, its high thermal stability and potential for integrating with other electronic materials make it a promising candidate for future electronic and optoelectronic devices. Ongoing research seeks to further explore its intrinsic properties and potential applications in devices such as transistors, photodetectors, and sensors.

More about PtSe2 (Platinum diselenide) →

Provenance

Version: 1 (snapshot c5c2f18)
Source page: refractiveindex.info
Original file: database/data/main/PtSe2/nk/Tharrault-4L.yml
ID: ds_852345059517
API: /v1/datasets/ds_852345059517

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