schinke_2015 ============ C\. Schinke, P\. C\. Peest, J\. Schmidt, R\. Brendel, K\. Bothe, M\. R\. Vogt, I\. Kröger, S\. Winter, A\. Schirmacher, S\. Lim, H\. T\. Nguyen and D\. MacDonald, "Uncertainty analysis for the coefficient of band\-to\-band absorption of crystalline silicon", AIP Adv\. 5, 067168 \(2015\) `Source record `__ · :doc:`Catalogue ` · :doc:`Review register ` DOI: `10\.1063/1\.4923379 `__ **Source kind:** measurement **Recorded technique:** Four methods at ISFH, PTB and ANU, each with a GUM uncertainty analysis \(Sections II\-III\), combined into one data set \(Section IV\)\. Spectroscopic ellipsometry \(J\. A\. Woollam M\-2000 UI, 60\-80 deg, WVASE32; a Si slab under a few nm of SiO2 with Herzinger's 2008 thermal\-oxide constants; Monte\-Carlo uncertainty\) at 250\-930 nm on a front\-polished Czochralski p\-type wafer, 5 Ohm cm, 1284 um\. Above 650 nm the ellipsometric alpha is replaced by a Tauc parametrisation alpha = \[beta \(hc/lambda \- E\_G\)\]^2 fitted at 650\-1050 nm to the ellipsometry and the reflectance/transmittance data, its uncertainty interpolated between those of the data at 650 and 930 nm \(PDF p\. 9\)\. Reflectance and transmittance \(RT; a Cary 5000 spectrophotometer with an integrating sphere at ISFH; a Cary 6000i and PTB's reference reflectometer at PTB\) on double\-side\-polished Czochralski p\-type wafers, 4\-6 Ohm cm, 653\.0 and 1284\.0 um thick; the RT alpha is corrected for free\-carrier absorption with the parametrisation of Green's 1995 book \(Ref\. 56\) at 3e15 cm^\-3 \(below 2 % below 1150 nm\)\. Electroluminescence \(EL, 1100\-1250 nm, polished lab cells, 711 um, 2\.5 Ohm cm\) scaled to the RT alpha at 1100\-1140 nm \(scale uncertainty 2\.8 %\); photoluminescence \(PL, 1200\-1450 nm, textured Al2O3\-passivated wafers\) scaled to the EL alpha at 1200\-1250 nm; spectral responsivity \(SR\) of solar cells at PTB \(1100\-1320 nm\)\. Overlapping results are combined as weighted means \(with hidden correlations for the ISFH RT data\)\. Sample temperature 295 \+\- 1 K \(ellipsometry, RT\) and 295 \+\- 0\.5 K \(EL, PL, SR\); the temperature uncertainty is included through the paper's c\_T \(Eq\. 22\)\. **Materials in structured entries:** Si **Dataset quantities:** absorption\_coefficient **Contents:** 1 dataset; 0 formulas. Curation notes -------------- Article 067168 = PDF pages 1\-23 \(page 1 is the publisher's cover sheet\); Table I \(Appendix A\) is on PDF pp\. 20\-21\. Identity checked against the first pages\. Open access \(CC BY 3\.0\)\. WHAT IS TABULATED\. Table I \('Coefficient of band\-to\-band absorption of crystalline silicon at 295 K and its relative uncertainty as determined in this work'\)\: alpha\_bb \(cm^\-1, four significant figures, each with its own power of ten\) and the relative expanded uncertainty U\(alpha\_bb\)/alpha\_bb \(%\), 250\-1450 nm at 10 nm steps \(121 rows\)\. Caption\: 'The uncertainty is specified for a coverage factor k = 2 and rounded to two significant digits'; the GUM expanded uncertainty with k = 2, 'approximately 95 %' \(PDF p\. 6\), recorded as relative\_rows with level '2 sigma'\. alpha\_bb is alpha less free\-carrier absorption \(corrections below 2 % \(RT\), 4\.5 % \(EL\) and about 6 % \(industrial SR cells\), each with an uncertainty equal to itself, rectangular\)\. The paper prints only alpha\: no n or k\. The wavelength medium is not stated; the difference between air and vacuum wavelengths \(about 0\.3 nm\) is far below the 10 nm grid and the uncertainties\. The paper says Table I is also provided in digital form as supplementary material \(Ref\. 58\); that file is not in the library, and Table I is complete without it\. UNCERTAINTY \(k = 2\)\. 0\.18\-0\.66 % at 250\-360 nm, rising through the absorption edge near 370 nm to 13 % at 630\-670 nm \(the ellipsometry's signal\-to\-noise falls as k/n falls\), down to 0\.98\-2 % at 900\-1060 nm \(RT\), then rising to 10\-13 % at 1170\-1220 nm, 22 % at 1240\-1250 nm, 36 % at 1350 nm and 180 % at 1450 nm\. The abstract and conclusion quote '0\.4% at 250 nm' and '12% at 1200 nm', where Table I prints 0\.26 and 11 \(12 at 1190 and 1210 nm\)\: the table's values are recorded; the paper does not explain the difference\. From 650 nm into the RT range the values are the Tauc parametrisation's, a smooth function, not individual measurements\. TEMPERATURE\. Table II \(Appendix B, PDF pp\. 21\-22\) gives c\_T = \(1/alpha\_bb\) d alpha\_bb/dT at 295 K \(Eq\. 22\), 250\-1450 nm, the mean of the ISFH ellipsometry, the ANU PL and Green \(2008\)'s coefficients, for use as alpha\(T\) = alpha\(T0\) \(T/T0\)^b, b = c\_T T0 \(Eqs\. 23\-24\)\. A normalised coefficient of alpha\: no quantity, not extracted\. COMPARISON IN THE PAPER \(Fig\. 16, PDF p\. 19\)\: deviations from the literature 'of the order of up to 30% relative'; good agreement with Green \(2008, green\_2008\) except beyond 1200 nm, where Green's alpha had given luminescence spectra at odds with measurement\. REFRACTIVEINDEX\.INFO\. main/Si/nk/Schinke\.yml \(data/external/refractiveindex\_info\) gives n and k at 0\.25\-1\.45 um citing this paper and M\. R\. Vogt's PhD thesis \(2015\); its n is not printed in the paper \(it comes from the thesis\) and is not used here; see the register entry for the comparison of k\. **Recorded bibliographic identity status:** VALIDATED. This concerns identification of the source; it does not establish the scientific correctness of its contents. Datasets -------- schinke\_2015/alpha\_295K ~~~~~~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "alpha_295K", "material": "Si", "file": "Si/schinke_2015__alpha_295K.csv", "table": "tbl_80266e561237", "quantity": "absorption_coefficient", "unit": "cm-1", "abscissa_unit": "nm", "use": "primary", "parameters": { "base": "e", "temperature_k": 295, "form": "bulk", "technique": "ellipsometry, reflectance/transmittance, luminescence and spectral responsivity, combined" }, "uncertainty": { "level": "2 sigma", "relative_rows": { "250": 0.0026, "260": 0.0028, "270": 0.0027, "280": 0.0028, "290": 0.0018, "300": 0.0019, "310": 0.002, "320": 0.0025, "330": 0.0032, "340": 0.003, "350": 0.0043, "360": 0.0066, "370": 0.011, "380": 0.017, "390": 0.024, "400": 0.03, "410": 0.037, "420": 0.043, "430": 0.05, "440": 0.055, "450": 0.061, "460": 0.068, "470": 0.075, "480": 0.078, "490": 0.08, "500": 0.083, "510": 0.089, "520": 0.093, "530": 0.11, "540": 0.12, "550": 0.11, "560": 0.11, "570": 0.1, "580": 0.1, "590": 0.11, "600": 0.11, "610": 0.12, "620": 0.12, "630": 0.13, "640": 0.13, "650": 0.13, "660": 0.13, "670": 0.13, "680": 0.12, "690": 0.12, "700": 0.11, "710": 0.11, "720": 0.1, "730": 0.098, "740": 0.093, "750": 0.089, "760": 0.084, "770": 0.079, "780": 0.074, "790": 0.07, "800": 0.065, "810": 0.06, "820": 0.055, "830": 0.051, "840": 0.046, "850": 0.041, "860": 0.037, "870": 0.032, "880": 0.028, "890": 0.023, "900": 0.019, "910": 0.015, "920": 0.012, "930": 0.01, "940": 0.0098, "950": 0.01, "960": 0.011, "970": 0.012, "980": 0.013, "990": 0.014, "1000": 0.014, "1010": 0.014, "1020": 0.015, "1030": 0.016, "1040": 0.018, "1050": 0.019, "1060": 0.02, "1070": 0.022, "1080": 0.022, "1090": 0.023, "1100": 0.025, "1110": 0.028, "1120": 0.032, "1130": 0.041, "1140": 0.058, "1150": 0.078, "1160": 0.088, "1170": 0.1, "1180": 0.11, "1190": 0.12, "1200": 0.11, "1210": 0.12, "1220": 0.13, "1230": 0.17, "1240": 0.22, "1250": 0.22, "1260": 0.2, "1270": 0.18, "1280": 0.17, "1290": 0.18, "1300": 0.18, "1310": 0.2, "1320": 0.24, "1330": 0.28, "1340": 0.33, "1350": 0.36, "1360": 0.38, "1370": 0.42, "1380": 0.5, "1390": 0.58, "1400": 0.75, "1410": 0.88, "1420": 1.2, "1430": 1.4, "1440": 1.7, "1450": 1.8 } } } Table I, PDF pp\. 20\-21 \(tbl\_80266e561237, tbl\_8c2f326870f4\)\: alpha\_bb of crystalline silicon at 295 K, 250\-1450 nm, 121 rows \(1\.804e6 to 9\.447e\-9 cm^\-1\), each cell's power of ten in e\-notation\. Relative uncertainty per row from the table \(k = 2\), checked against the table by the extraction script\. Combined from ellipsometry, RT, EL, PL and SR; from 650 nm into the RT range a Tauc parametrisation \(source notes\)\. Formulas -------- No formulas are recorded. Corrections ----------- No dataset errata are recorded in this source record. Formula corrections, where recorded, appear with their formulas above. Curation notes may also discuss corrections or unresolved interpretation. Consult the :doc:`review register ` for the checks and decisions.