Mercury - Cadmium - Tellurium alloy  

Sample preparation


For details, please refer to the following paper published in the 2004 II-VI Workshop Proceedings:
Detailed Study Of Above Bandgap Optical Absorption In HgCdTe and Application to Infrared Detector Photo-Response

K. Moazzami  and J. Phillips
Department of Electrical Engineering and Computer Science
The University of Michigan
Ann Arbor, Michigan 48109-2122

D. Lee
Rockwell Scientific Company
Camarillo, California 93012

S. Krishnamurthy
SRI International
Menlo Park, California 94025

G. Benoit and Y. Fink
Department of Materials Science and Engineering
Massachusetts Institute of Technology
Cambridge MA 02139

Measurement and analysis

We performed all measurements (Visible to Infra-Red) at an incidence angle of 73 degrees. To extract the thickness of the deposited film, the ellipsometric parameters were fitted in the region of low absorption using the Levenberg-Marquardt regression method with a Cauchy-like dispersion relation:

n=A+B/λ2+c/λ4

k=D/λ+E/λ3+F/λ5

where λ is the wavelength and A,B,C,D,E,F are fitting parameters. The deduced dispersion relation was used to generate starting values in the Levenberg-Marquardt regression method to calculate the n and k values at every wavelength (independently of any model). In the regions of large absorption, the film was treated as a bulk sample and n and k values were calculated at all wavelengths without any assumption. The standard deviations of the fits were ~ 10-3 and the corresponding film’s thicknesses were equal to 23 microns for both Hg1-0.223Cd0.223Te and Hg1-0.271 Cd0.271Te.

Results

 

   
 Hg 1-0.223
Cd0.223Te


 Hg 1-0.271
Cd0.271Te


Energy (eV)
 n k
 Energy (eV)
 n
 k
0.062
0.0635
0.0651
0.0667
0.0682
0.0698
0.0713
0.0729
0.0744
0.076
0.0776
0.0791
0.0807
0.0822
0.0838
0.0853
0.0869
0.0884
0.09
0.0916
0.0931
0.0947
0.0962
0.0978
0.0993
0.1009
0.1024
0.104
0.1056
0.1071
0.1087
0.1102
0.1118
0.1133
0.1149
0.1164
0.118
0.1196
0.1211
0.1227
0.1242
0.1258
0.1273
0.1289
0.1304
0.132
0.1336
0.1351
0.1367
0.1382
0.1398
0.1413
0.1429
0.1444
0.146
0.1476
0.1491
0.1507
0.1522
0.1538
0.1553
0.1568
0.1616
0.1663
0.1711
0.1758
0.1806
0.1853
0.1901
0.1948
0.1996
0.2043
0.2091
0.2138
0.2186
0.2233
0.2281
0.2329
0.2376
0.2424
0.2471
0.2519
0.2566
0.2614
0.2661
0.2709
0.2756
0.2804
0.2851
0.2899
0.2946
0.2994
0.3042
0.3089
0.3137
0.3184
0.3232
0.3279
0.3327
0.3374
0.3422
0.3469
0.3517
0.3564
0.3612
0.3659
0.3707
0.3755
0.3802
0.385
0.3897
0.3945
0.3992
0.404
0.4087
0.4135
0.4182
0.423
0.4277
0.4325
0.4372
0.442
0.4468
0.4515
0.4563
0.461
0.4658
0.4705
0.4753
0.48
0.4848
0.4895
0.4943
0.499
0.5038
0.5085
0.5133
0.5181
0.5228
0.5276
0.5323
0.5371
0.5418
0.5466
0.5513
0.5561
0.5608
0.5656
0.5703
0.5751
0.5798
0.5846
0.5893
0.5941
0.5989
0.6036
0.6084
0.6131
0.6179
0.6036
0.6084
0.6131
0.6179
0.62
0.66
0.7
0.74
0.78
0.82
0.86
0.9
0.94
0.98
1.02
1.06
1.1
1.14
1.18
1.22
1.26
1.3
1.34
1.38
1.42
1.46
1.5
1.54
1.58
1.62
1.66
1.7
1.74
1.78
1.82
1.86
1.9
1.94
1.98
2.02
2.06
2.1
2.14
2.18
2.22
2.26
2.3
2.34
2.38
2.42
2.46
2.5
2.54
2.58
2.62
2.66
2.7
2.74
2.78
2.82
2.86
2.9
2.94
2.98
3.02
3.06
3.1
3.14
3.18
3.22
3.26
3.3
3.34
3.38
3.42
3.46
3.5
3.54
3.58
3.62
3.66
3.7
3.74
3.78
3.82
3.86
3.9
3.94
3.98
4.02
4.06
4.1
4.14


 3.375
3.375
3.375
3.375
3.375
3.376
3.376
3.376
3.376
3.376
3.376
3.376
3.376
3.376
3.376
3.376
3.376
3.376
3.376
3.376
3.376
3.376
3.376
3.377
3.376
3.377
3.377
3.377
3.377
3.377
3.377
3.377
3.377
3.377
3.377
3.377
3.377
3.377
3.377
3.377
3.377
3.377
3.377
3.377
3.377
3.377
3.377
3.378
3.378
3.378
3.378
3.378
3.378
3.378
3.378
3.379
3.379
3.379
3.379
3.379
3.379
3.381
3.387
3.391
3.400
3.416
3.437
3.460
3.482
3.500
3.517
3.530
3.539
3.541
3.537
3.530
3.522
3.515
3.509
3.503
3.498
3.493
3.488
3.481
3.475
3.469
3.463
3.457
3.453
3.449
3.445
3.441
3.438
3.434
3.431
3.427
3.424
3.421
3.417
3.414
3.411
3.407
3.403
3.399
3.396
3.394
3.392
3.389
3.386
3.382
3.379
3.376
3.375
3.373
3.372
3.370
3.368
3.366
3.364
3.362
3.360
3.358
3.355
3.353
3.352
3.350
3.349
3.348
3.347
3.345
3.344
3.343
3.343
3.343
3.343
3.343
3.342
3.342
3.342
3.342
3.341
3.340
3.340
3.339
3.338
3.338
3.338
3.338
3.337
3.337
3.337
3.336
3.337
3.337
3.337
3.336
3.336
3.335
3.335
3.336
3.336
3.335
3.335
3.334
3.336
3.337
3.338
3.339
3.339
3.340
3.341
3.342
3.345
3.348
3.352
3.356
3.359
3.362
3.366
3.371
3.376
3.383
3.390
3.398
3.406
3.415
3.424
3.434
3.444
3.454
3.466
3.479
3.493
3.508
3.521
3.533
3.546
3.560
3.572
3.582
3.589
3.593
3.582
3.542
3.462
3.356
3.247
3.159
3.098
3.057
3.027
3.001
2.977
2.956
2.938
2.919
2.901
2.878
2.847
2.806
2.754
2.692
2.626
2.563
2.508
2.466
2.434
2.408
2.384
2.362
2.343
2.328
2.315
2.301
2.287
2.275
2.265
2.258
2.252
2.247
2.243
2.238
2.234
2.231
2.229
2.227
2.226
2.225
2.225
2.224
2.221
2.213

 0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000001
0.000002
0.000004
0.000006
0.000008
0.000012
0.000018
0.000025
0.000082
0.000132
0.000183
0.000507
0.00152
0.00167
0.00171
0.00282
0.00345
0.00511
0.0103
0.0222
0.0491
0.0999
0.170
0.241
0.288
0.307
0.309
0.309
0.311
0.312
0.312
0.313
0.313
0.313
0.313
0.313
0.314
0.314
0.314
0.314
0.314
0.314
0.315
0.315
0.315
0.315
0.315
0.316
0.316
0.317
0.317
0.318
0.318
0.318
0.319
0.319
0.319
0.319
0.320
0.320
0.321
0.321
0.321
0.322
0.322
0.322
0.323
0.323
0.323
0.323
0.323
0.323
0.323
0.323
0.323
0.324
0.324
0.324
0.324
0.325
0.325
0.325
0.325
0.325
0.325
0.325
0.326
0.326
0.326
0.326
0.326
0.326
0.326
0.326
0.326
0.327
0.327
0.327
0.327
0.327
0.328
0.328
0.328
0.328
0.328
0.329
0.328
0.328
0.328
0.329
0.339
0.343
0.345
0.346
0.348
0.351
0.354
0.357
0.361
0.367
0.375
0.384
0.394
0.406
0.419
0.434
0.452
0.472
0.494
0.517
0.541
0.569
0.598
0.626
0.651
0.674
0.697
0.722
0.752
0.786
0.821
0.854
0.888
0.928
0.977
1.034
1.097
1.159
1.232
1.328
1.443
1.559
1.637
1.661
1.649
1.626
1.610
1.604
1.602
1.608
1.621
1.636
1.654
1.674
1.698
1.729
1.763
1.793
1.812
1.817
1.810
1.794
1.770
1.744
1.719
1.696
1.678
1.662
1.644
1.628
1.612
1.598
1.587
1.578
1.570
1.563
1.556
1.551
1.547
1.544
1.543
1.543
1.545
1.548
1.552
1.557
1.563
1.571
1.584

 0.0689
0.0713
0.0737
0.0761
0.0785
0.0809
0.0833
0.0858
0.0882
0.0906
0.093
0.0954
0.0978
0.1002
0.1026
0.105
0.1075
0.1099
0.1123
0.1147
0.1171
0.1195
0.1219
0.1243
0.1267
0.1292
0.1316
0.134
0.1364
0.1388
0.1412
0.1436
0.146
0.1484
0.1508
0.1533
0.1557
0.1581
0.1605
0.1629
0.1653
0.1677
0.1701
0.1725
0.175
0.1774
0.1798
0.1822
0.1846
0.187
0.1894
0.1918
0.1942
0.1967
0.1991
0.2015
0.2039
0.2063
0.2087
0.2111
0.2135
0.2159
0.2184
0.2208
0.2232
0.2256
0.228
0.2304
0.2328
0.2352
0.2376
0.24
0.2425
0.2449
0.2473
0.2497
0.2521
0.2545
0.2569
0.2593
0.2617
0.2642
0.2666
0.269
0.2714
0.2738
0.2762
0.2786
0.281
0.2834
0.2859
0.2883
0.2907
0.2931
0.2955
0.2979
0.3003
0.3027
0.3051
0.3076
0.3099
0.3118
0.3137
0.3156
0.3175
0.3195
0.3214
0.3233
0.3252
0.3271
0.329
0.3309
0.3328
0.3348
0.3367
0.3386
0.3405
0.3424
0.3443
0.3462
0.3481
0.3501
0.352
0.3539
0.3558
0.3577
0.3596
0.3615
0.3635
0.3654
0.3673
0.3692
0.3711
0.373
0.3749
0.3768
0.3788
0.3807
0.3826
0.3845
0.3864
0.3883
0.3902
0.3921
0.3941
0.396
0.3979
0.3998
0.4017
0.4036
0.4055
0.4074
0.4094
0.4113
0.4132
0.4151
0.417
0.4189
0.4208
0.4228
0.4247
0.4266
0.4285
0.4304
0.4323
0.4342
0.4361
0.4381
0.44
0.4419
0.4438
0.4457
0.4476
0.4495
0.4514
0.4534
0.4553
0.4572
0.4591
0.461
0.4629
0.4648
0.4667
0.4687
0.4706
0.4725
0.4744
0.4763
0.4782
0.4801
0.4821
0.484
0.4859
0.4878
0.4897
0.4916
0.4935
0.4954
0.4974
0.4993
0.5012
0.5031
0.505
0.5069
0.5088
0.5107
0.5127
0.5146
0.5165
0.5184
0.5203
0.5222
0.5241
0.526
0.528
0.5299
0.5318
0.5337
0.5356
0.5375
0.5394
0.5414
0.5433
0.5452
0.5471
0.549
0.5509
0.5528
0.5547
0.5567
0.5586
0.5605
0.5624
0.5643
0.5662
0.5681
0.57
0.572
0.5739
0.5758
0.5777
0.5796
0.5815
0.5834
0.5853
0.5873
0.5892
0.5911
0.593
0.5949
0.5968
0.5987
0.6007
0.6026
0.6045
0.6064
0.6083
0.6102
0.6121
0.614
0.616
0.6179
0.62
0.66
0.7
0.74
0.78
0.82
0.86
0.9
0.94
0.98
1.02
1.06
1.1
1.14
1.18
1.22
1.26
1.3
1.34
1.38
1.42
1.46
1.5
1.54
1.58
1.62
1.66
1.7
1.74
1.78
1.82
1.86
1.9
1.94
1.98
2.02
2.06
2.1
2.14
2.18
2.22
2.26
2.3
2.34
2.38
2.42
2.46
2.5
2.54
2.58
2.62
2.66
2.7
2.74
2.78
2.82
2.86
2.9
2.94
2.98
3.02
3.06
3.1
3.14
3.18
3.22
3.26
3.3
3.34
3.38
3.42
3.46
3.5
3.54
3.58
3.62
3.66
3.7
3.74
3.78
3.82
3.86
3.9
3.94
3.98
4.02
4.06
4.1
4.14

 3.349
3.350
3.350
3.350
3.350
3.350
3.350
3.350
3.350
3.350
3.350
3.350
3.350
3.350
3.350
3.350
3.350
3.350
3.351
3.351
3.351
3.351
3.351
3.351
3.352
3.352
3.352
3.352
3.352
3.353
3.353
3.353
3.354
3.354
3.355
3.355
3.355
3.356
3.356
3.357
3.358
3.359
3.359
3.360
3.361
3.362
3.362
3.363
3.364
3.365
3.366
3.368
3.370
3.371
3.373
3.374
3.375
3.376
3.378
3.379
3.381
3.383
3.385
3.387
3.389
3.391
3.394
3.397
3.401
3.405
3.410
3.416
3.422
3.428
3.435
3.443
3.451
3.458
3.459
3.454
3.446
3.437
3.430
3.424
3.419
3.413
3.407
3.401
3.395
3.390
3.386
3.383
3.379
3.376
3.372
3.369
3.365
3.363
3.361
3.358
3.355
3.354
3.352
3.350
3.348
3.346
3.344
3.342
3.340
3.338
3.336
3.334
3.332
3.331
3.329
3.328
3.326
3.324
3.322
3.320
3.319
3.317
3.316
3.314
3.313
3.311
3.310
3.308
3.307
3.306
3.305
3.303
3.302
3.300
3.299
3.297
3.296
3.295
3.294
3.292
3.291
3.290
3.289
3.287
3.286
3.285
3.284
3.284
3.283
3.282
3.281
3.279
3.278
3.277
3.276
3.275
3.275
3.273
3.272
3.270
3.269
3.268
3.267
3.267
3.266
3.265
3.264
3.263
3.261
3.260
3.259
3.258
3.257
3.256
3.255
3.254
3.253
3.252
3.251
3.250
3.249
3.248
3.247
3.246
3.246
3.245
3.244
3.243
3.242
3.241
3.240
3.239
3.239
3.238
3.237
3.236
3.236
3.234
3.233
3.232
3.231
3.230
3.230
3.229
3.228
3.227
3.226
3.225
3.224
3.223
3.222
3.221
3.220
3.220
3.219
3.218
3.217
3.216
3.215
3.215
3.214
3.214
3.213
3.213
3.212
3.211
3.211
3.210
3.210
3.210
3.209
3.209
3.209
3.209
3.209
3.208
3.208
3.207
3.207
3.207
3.207
3.207
3.207
3.206
3.206
3.205
3.205
3.205
3.204
3.203
3.202
3.202
3.203
3.203
3.202
3.202
3.202
3.201
3.201
3.202
3.202
3.201
3.210
3.211
3.213
3.214
3.215
3.216
3.218
3.219
3.221
3.222
3.223
3.225
3.226
3.227
3.228
3.230
3.231
3.232
3.234
3.235
3.236
3.238
3.241
3.244
3.246
3.248
3.251
3.257
3.263
3.269
3.275
3.281
3.286
3.292
3.297
3.302
3.306
3.306
3.304
3.296
3.273
3.225
3.150
3.054
2.957
2.877
2.822
2.787
2.762
2.740
2.720
2.702
2.684
2.663
2.640
2.615
2.583
2.545
2.495
2.439
2.385
2.333
2.285
2.244
2.210
2.189
2.170
2.155
2.143
2.127
2.112
2.096
2.082
2.075
2.070
2.062
2.054
2.048
2.043
2.039
2.035
2.030
2.024
2.016
2.009
2.003
1.998
1.993
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