High Throughput Light Absorber Discovery, Part 1: An Algorithm for Automated Tauc Analysis.

High-throughput experimentation provides efficient mapping of composition-property relationships, and its implementation for the discovery of optical materials enables advancements in solar energy and other technologies. In a high throughput pipeline, automated data processing algorithms are often required to match experimental throughput, and we present an automated Tauc analysis algorithm for estimating band gap energies from optical spectroscopy data. The algorithm mimics the judgment of an expert scientist, which is demonstrated through its application to a variety of high throughput spectroscopy data, including the identification of indirect or direct band gaps in Fe2O3, Cu2V2O7, and BiVO4. The applicability of the algorithm to estimate a range of band gap energies for various materials is demonstrated by a comparison of direct-allowed band gaps estimated by expert scientists and by automated algorithm for 60 optical spectra.

[1]  N. Mott,et al.  Conduction in non-crystalline systems V. Conductivity, optical absorption and photoconductivity in amorphous semiconductors , 1970 .

[2]  N. Ghobadi,et al.  Band gap determination using absorption spectrum fitting procedure , 2013, International Nano Letters.

[3]  John D. Perkins,et al.  Inverse design approach to hole doping in ternary oxides: Enhancing p-type conductivity in cobalt oxide spinels , 2011 .

[4]  A. Murphy.  Band-gap determination from diffuse reflectance measurements of semiconductor films, and application to photoelectrochemical water-splitting , 2007 .

[5]  U. Pal,et al.  Use of diffuse reflectance spectroscopy for optical characterization of un-supported nanostructures , 2007 .

[6]  A. Murphy,et al.  Optical properties of an optically rough coating from inversion of diffuse reflectance measurements. , 2007, Applied optics.

[7]  V. Drobny,et al.  Properties of reactively-sputtered copper oxide thin films , 1979 .

[8]  R. V. Dover,et al.  Improved conductivity of ZnO through codoping with In and Al , 2009 .

[9]  John Gregoire.  High throughput discovery of solar fuels photoanodes , 2017 .

[10]  S. Suram,et al.  High-throughput on-the-fly scanning ultraviolet-visible dual-sphere spectrometer. , 2015, The Review of scientific instruments.

[11]  D. Ginley,et al.  Optical analysis of thin film combinatorial libraries , 2004 .

[12]  K. Poeppelmeier,et al.  Direct optical band gap measurement in polycrystalline semiconductors: A critical look at the Tauc method , 2016 .

[13]  R. Grigorovici,et al.  Optical Properties and Electronic Structure of Amorphous Germanium , 1966, 1966.

[14]  A. Savitzky,et al.  Smoothing and Differentiation of Data by Simplified Least Squares Procedures. , 1964 .

[15]  Lin-wang Wang,et al.  Bandgap Tunability in Sb‐Alloyed BiVO4 Quaternary Oxides as Visible Light Absorbers for Solar Fuel Applications , 2015, Advanced materials.

[16]  E. Burstein.  Anomalous Optical Absorption Limit in InSb , 1954 .

[17]  Zongyou Yin,et al.  A review of energy bandgap engineering in III–V semiconductor alloys for mid-infrared laser applications , 2007 .

[18]  Nathan S. Lewis,et al.  An analysis of the optimal band gaps of light absorbers in integrated tandem photoelectrochemical water-splitting systems , 2013 .

[19]  Karl-Fredrik Berggren,et al.  Band-gap narrowing in heavily doped many-valley semiconductors , 1981 .

[20]  Optical absorption coefficient and thickness measurement of electrodeposited films of Cu2O , 1987 .

[21]  R. Asahi,et al.  Visible-Light Photocatalysis in Nitrogen-Doped Titanium Oxides , 2001, Science.

[22]  M. Saleem,et al.  Optical properties of iron oxide (α-Fe2O3) thin films deposited by the reactive evaporation of iron , 2012 .

[23]  A. Walsh,et al.  The nature of electron lone pairs in BiVO4 , 2011 .

[24]  P. Kubelka,et al.  Errata: New Contributions to the Optics of Intensely Light-Scattering Materials. Part I , 1948 .

[25]  Hagit Aviv,et al.  Quantum Efficiency and Bandgap Analysis for Combinatorial Photovoltaics: Sorting Activity of Cu–O Compounds in All-Oxide Device Libraries , 2014, ACS combinatorial science.

[26]  D. L. Wood,et al.  Weak Absorption Tails in Amorphous Semiconductors , 1972 .

[27]  H. Fujiwara,et al.  Spectroscopic Ellipsometry: Principles and Applications , 2007 .

[29]  S. Roberts.  Optical Properties of Copper , 1960 .

[30]  T. Moss.  RESEARCH NOTES: Theory of the Spectral Distribution of Recombination Radiation from InSb , 1957 .

[31]  J. Tauc,et al.  Optical and Magnetic Investigations of the Localized States in Semiconducting Glasses , 1970 .

[32]  Yoshihiro Hishikawa,et al.  Interference-Free Determination of the Optical Absorption Coefficient and the Optical Gap of Amorphous Silicon Thin Films , 1991 .

[33]  D. F. Swinehart,et al.  The Beer-Lambert Law , 1962 .

[34]  Paul F. Ndione,et al.  Design of Semiconducting Tetrahedral Mn 1 − x Zn x O Alloys and Their Application to Solar Water Splitting , 2015 .

[35]  E. Gornik.  Recombination Radiation from Impact-Ionized Shallow Donors in n-Type InSb , 1972 .