Optical constants

Refractive index of CdTe (Cadmium telluride)

DeBell et al. 1979: n 6–22 µm; 20 K

Data: formula 2
Range: 6–22 µm
Licence: CC0-1.0

Axis Log x Log y

Click the plot to set the calculator wavelength.

At one wavelength

Refractive index n: 2.64233
Extinction coefficient k: 0

Permittivity ε₁: 6.98189
Permittivity ε₂: 0

Absorption coefficient α: 0 cm⁻¹
Penetration depth δ = λ/(2πk): — nm

Abbe number V_d: —
Chromatic dispersion dn/dλ: -0.00293344 µm⁻¹

Group index n_g: 2.67606
Group velocity dispersion: -610.95 fs²/mm

Dispersion parameter D: 8.70183 ps/(nm·km)
Photon energy: 0.107812 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

# CdTe (Cadmium telluride): DeBell et al. 1979: n 6–22 µm; 20 K
cdte = ls.fetch_refractiveindex("main", "CdTe", "DeBell-20K", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(cdte.range_nm)  # (6000, 22000) nm
eps = cdte.eps([11500])  # 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_3dbc8f5aed31/lightsmith"
cdte = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(cdte.source)  # citation and provenance travel with the data

Any dataset here, as the library's Tabulated material (cdte/debell-1979-20k).

# ... load cdte as above, then:
sim = ls.Simulation(
    particles=[ls.Particle(shape=ls.Sphere(radius_nm=50), material=cdte)],
    medium_index=1.0,
    wavelengths=ls.WavelengthRange(start_nm=6000, stop_nm=22000, 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"]).

import json, urllib.request
import lightsmith as ls

url = "https://materials.lightsmith.dev/v1/datasets/ds_3dbc8f5aed31/lightsmith?model=drude_lorentz"
cdte_dl = ls.DrudeLorentz.model_validate(json.load(urllib.request.urlopen(url)))

A dispersive Drude–Lorentz model for time-domain solvers.

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.

Dispersion formula

Sellmeier (C in µm²) (formula 2), λ in µm

n^{2} - 1 = \frac{6.0599879 λ^{2}}{λ^{2} - 0.1004272} + \frac{3.7564378 λ^{2}}{λ^{2} - 6138.789}

Valid from 6.0 to 22.0 µm.

Coefficients as stored

C_i	Value
C1	0.0
C2	6.0599879
C3	0.1004272
C4	3.7564378
C5	6138.789

Comments and conditions

20 K (-253.1 °C)

References

A. G. DeBell, E. L. Dereniak, J. Harvey, J. Nissley, J. Palmer, A. Selvarajan, W. L. Wolfe. Cryogenic refractive indices and temperature coefficients of cadmium telluride from 6 µm to 22 µm. Appl. Opt. 18, 3114-3115 (1979)

doi:10.1364/ao.18.003114 Cryogenic refractive indices and temperature coefficients of cadmium telluride from 6 μm to 22 μm, Applied Optics (1979)

Cite

A. G. DeBell et al.. Cryogenic refractive indices and temperature coefficients of cadmium telluride from 6 μm to 22 μm. Applied Optics, 18, 3114 (1979), doi:10.1364/ao.18.003114; Data from the refractiveindex.info database (M. N. Polyanskiy, Sci. Data 11, 94 (2024), doi:10.1038/s41597-023-02898-2)

Data

Computed on 400 wavelengths, the same grid as the API and the library

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

CdTe (Cadmium telluride), DeBell et al. 1979: n 6–22 µm; 20 K: n and k versus wavelength
λ (µm)	n
6	2.656084
6.01957	2.656036
6.0392	2.655987
6.0589	2.655939
6.07866	2.655891
6.09849	2.655842
6.11838	2.655794
6.13834	2.655745
6.15836	2.655697
6.17844	2.655648
6.1986	2.6556
6.21881	2.655551
6.2391	2.655502
6.25945	2.655453
6.27986	2.655404
6.30035	2.655355
6.3209	2.655306
6.34151	2.655257
6.3622	2.655208
6.38295	2.655158
6.40377	2.655109
6.42465	2.655059
6.44561	2.65501
6.46663	2.65496
6.48772	2.65491
6.50889	2.65486
6.53011	2.65481
6.55141	2.65476
6.57278	2.65471
6.59422	2.65466
6.61573	2.654609
6.63731	2.654559
6.65896	2.654508
6.68067	2.654457
6.70246	2.654406
6.72433	2.654355
6.74626	2.654304
6.76826	2.654253
6.79034	2.654202
6.81249	2.65415
6.83471	2.654099
6.857	2.654047
6.87936	2.653995
6.9018	2.653943
6.92431	2.653891
6.9469	2.653839
6.96956	2.653786
6.99229	2.653734
7.01509	2.653681
7.03798	2.653628
7.06093	2.653575
7.08396	2.653522
7.10707	2.653469
7.13025	2.653415
7.1535	2.653362
7.17684	2.653308
7.20024	2.653254
7.22373	2.6532
7.24729	2.653145
7.27093	2.653091
7.29464	2.653036
7.31844	2.652981
7.34231	2.652926
7.36625	2.652871
7.39028	2.652816
7.41439	2.65276
7.43857	2.652704
7.46283	2.652648
7.48717	2.652592
7.51159	2.652536
7.53609	2.652479
7.56067	2.652422
7.58533	2.652365
7.61007	2.652308
7.6349	2.652251
7.6598	2.652193
7.68478	2.652135
7.70985	2.652077
7.73499	2.652019
7.76022	2.651961
7.78553	2.651902
7.81093	2.651843
7.8364	2.651784
7.86196	2.651724
7.88761	2.651665
7.91333	2.651605
7.93914	2.651545
7.96504	2.651484
7.99102	2.651424
8.01708	2.651363
8.04323	2.651302
8.06946	2.65124
8.09578	2.651179
8.12219	2.651117
8.14868	2.651055
8.17526	2.650992
8.20193	2.65093
8.22868	2.650867
8.25552	2.650803
8.28244	2.65074
8.30946	2.650676
8.33656	2.650612
8.36375	2.650547
8.39103	2.650483
8.4184	2.650418
8.44586	2.650353
8.4734	2.650287
8.50104	2.650221
8.52877	2.650155
8.55659	2.650089
8.5845	2.650022
8.6125	2.649955
8.64059	2.649887
8.66877	2.649819
8.69704	2.649751
8.72541	2.649683
8.75387	2.649614
8.78242	2.649545
8.81107	2.649476
8.83981	2.649406
8.86864	2.649336
8.89756	2.649266
8.92659	2.649195
8.9557	2.649124
8.98491	2.649052
9.01422	2.648981
9.04362	2.648908
9.07312	2.648836
9.10271	2.648763
9.1324	2.64869
9.16219	2.648616
9.19207	2.648542
9.22205	2.648467
9.25213	2.648393
9.28231	2.648317
9.31258	2.648242
9.34296	2.648166
9.37343	2.648089
9.404	2.648013
9.43468	2.647936
9.46545	2.647858
9.49632	2.64778
9.5273	2.647701
9.55837	2.647623
9.58955	2.647543
9.62082	2.647464
9.6522	2.647383
9.68369	2.647303
9.71527	2.647222
9.74696	2.64714
9.77875	2.647059
9.81065	2.646976
9.84264	2.646893
9.87475	2.64681
9.90696	2.646726
9.93927	2.646642
9.97169	2.646558
10.0042	2.646472
10.0368	2.646387
10.0696	2.646301
10.1024	2.646214
10.1354	2.646127
10.1684	2.64604
10.2016	2.645951
10.2349	2.645863
10.2683	2.645774
10.3017	2.645684
10.3353	2.645594
10.3691	2.645504
10.4029	2.645412
10.4368	2.645321
10.4708	2.645229
10.505	2.645136
10.5393	2.645043
10.5736	2.644949
10.6081	2.644854
10.6427	2.644759
10.6774	2.644664
10.7123	2.644568
10.7472	2.644471
10.7823	2.644374
10.8174	2.644276
10.8527	2.644178
10.8881	2.644079
10.9236	2.643979
10.9593	2.643879
10.995	2.643779
11.0309	2.643677
11.0668	2.643575
11.1029	2.643473
11.1391	2.64337
11.1755	2.643266
11.2119	2.643161
11.2485	2.643056
11.2852	2.642951
11.322	2.642844
11.3589	2.642737
11.396	2.64263
11.4331	2.642521
11.4704	2.642412
11.5078	2.642303
11.5454	2.642192
11.583	2.642081
11.6208	2.64197
11.6587	2.641857
11.6967	2.641744
11.7349	2.64163
11.7732	2.641516
11.8116	2.641401
11.8501	2.641285
11.8888	2.641168
11.9275	2.641051
11.9664	2.640932
12.0055	2.640814
12.0446	2.640694
12.0839	2.640574
12.1233	2.640452
12.1629	2.64033
12.2025	2.640208
12.2423	2.640084
12.2823	2.63996
12.3223	2.639835
12.3625	2.639709
12.4028	2.639582
12.4433	2.639455
12.4839	2.639327
12.5246	2.639198
12.5654	2.639068
12.6064	2.638937
12.6475	2.638805
12.6888	2.638673
12.7302	2.63854
12.7717	2.638405
12.8134	2.63827
12.8552	2.638134
12.8971	2.637998
12.9392	2.63786
12.9814	2.637721
13.0237	2.637582
13.0662	2.637441
13.1088	2.6373
13.1515	2.637158
13.1944	2.637014
13.2375	2.63687
13.2807	2.636725
13.324	2.636579
13.3674	2.636432
13.411	2.636284
13.4548	2.636135
13.4987	2.635985
13.5427	2.635834
13.5869	2.635683
13.6312	2.63553
13.6756	2.635376
13.7202	2.635221
13.765	2.635065
13.8099	2.634908
13.8549	2.63475
13.9001	2.63459
13.9455	2.63443
13.9909	2.634269
14.0366	2.634107
14.0824	2.633943
14.1283	2.633778
14.1744	2.633613
14.2206	2.633446
14.267	2.633278
14.3135	2.633109
14.3602	2.632939
14.407	2.632768
14.454	2.632595
14.5012	2.632421
14.5485	2.632247
14.5959	2.632071
14.6435	2.631893
14.6913	2.631715
14.7392	2.631535
14.7873	2.631354
14.8355	2.631172
14.8839	2.630989
14.9325	2.630804
14.9812	2.630618
15.03	2.630431
15.079	2.630243
15.1282	2.630053
15.1776	2.629862
15.2271	2.62967
15.2767	2.629476
15.3266	2.629281
15.3766	2.629085
15.4267	2.628887
15.477	2.628688
15.5275	2.628487
15.5782	2.628286
15.629	2.628082
15.6799	2.627878
15.7311	2.627672
15.7824	2.627464
15.8339	2.627255
15.8855	2.627045
15.9373	2.626833
15.9893	2.626619
16.0415	2.626404
16.0938	2.626188
16.1463	2.62597
16.1989	2.625751
16.2518	2.62553
16.3048	2.625307
16.358	2.625083
16.4113	2.624858
16.4648	2.62463
16.5185	2.624401
16.5724	2.624171
16.6265	2.623939
16.6807	2.623705
16.7351	2.62347
16.7897	2.623233
16.8445	2.622994
16.8994	2.622753
16.9545	2.622511
17.0098	2.622267
17.0653	2.622022
17.121	2.621774
17.1768	2.621525
17.2328	2.621274
17.289	2.621021
17.3454	2.620767
17.402	2.620511
17.4588	2.620252
17.5157	2.619992
17.5728	2.61973
17.6302	2.619467
17.6877	2.619201
17.7453	2.618933
17.8032	2.618664
17.8613	2.618392
17.9196	2.618119
17.978	2.617843
18.0366	2.617566
18.0955	2.617286
18.1545	2.617005
18.2137	2.616721
18.2731	2.616435
18.3327	2.616148
18.3925	2.615858
18.4525	2.615566
18.5127	2.615272
18.5731	2.614976
18.6336	2.614677
18.6944	2.614377
18.7554	2.614074
18.8166	2.613769
18.8779	2.613462
18.9395	2.613152
19.0013	2.612841
19.0633	2.612526
19.1254	2.61221
19.1878	2.611891
19.2504	2.61157
19.3132	2.611247
19.3762	2.610921
19.4394	2.610592
19.5028	2.610262
19.5664	2.609928
19.6302	2.609593
19.6942	2.609255
19.7585	2.608914
19.8229	2.608571
19.8876	2.608225
19.9525	2.607876
20.0175	2.607525
20.0828	2.607172
20.1483	2.606815
20.214	2.606456
20.28	2.606094
20.3461	2.60573
20.4125	2.605363
20.4791	2.604993
20.5459	2.60462
20.6129	2.604244
20.6801	2.603866
20.7476	2.603485
20.8152	2.6031
20.8831	2.602713
20.9512	2.602323
21.0196	2.60193
21.0881	2.601534
21.1569	2.601135
21.2259	2.600732
21.2951	2.600327
21.3646	2.599919
21.4343	2.599507
21.5042	2.599093
21.5743	2.598675
21.6447	2.598254
21.7153	2.597829
21.7861	2.597402
21.8572	2.596971
21.9285	2.596536
22	2.596099

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: —

CdTe (Cadmium telluride): all datasets

Experimental data

Models and simulations

Adachi et al. 1993: n,k 0.221–1.13 µm n,k 0.2214–1.127 µm

About CdTe (Cadmium telluride)

Cadmium telluride (CdTe) is an inorganic compound that typically crystallizes in a cubic zincblende structure. It is a direct bandgap semiconductor with a bandgap energy of approximately 1.5 eV, making it highly suitable for photovoltaic applications, especially thin-film solar cells. CdTe solar cells are commercially significant due to their lower manufacturing costs and competitive efficiency levels compared to silicon-based cells. Besides photovoltaics, CdTe is also employed in infrared detectors, radiation detectors, and electro-optic modulators. However, the presence of cadmium, a toxic heavy metal, calls for stringent handling and disposal protocols and has prompted research into recycling methods. Synthesis methods for CdTe include physical vapor deposition, chemical vapor deposition, and close-spaced sublimation, among others, each offering unique advantages in terms of film quality and manufacturing scalability. Despite the environmental concerns related to its toxicity, CdTe remains a highly relevant material in renewable energy technologies and continues to attract research efforts aimed at mitigating its environmental impact.

Cadmium telluride - Wikipedia

More about CdTe (Cadmium telluride) →

Provenance

Version: 1 (snapshot c5c2f18)
Source page: refractiveindex.info
Original file: database/data/main/CdTe/nk/DeBell-20K.yml
ID: ds_3dbc8f5aed31
API: /v1/datasets/ds_3dbc8f5aed31

Plot