A Detailed Study on the Structural, Electrical and Optical Properties of (ZnO-GeO2) Substituted In2O3 Transparent Conducting Oxide

In this study, ZnO and GeO2 substituted In2O3 ternary system is investigated with various characterization methods for optical, electrical and structural properties. This new transparent conducting oxide prepared different composition which can be symbolized as ZnxIn2-2xGexO3 0.1 ≤ ? ≤ 0.5. The optical properties of the samples obtained show that the optical band gap enhances from 2.94 eV to 3.16 eV with the augmentation of the x value. Conductivity values for ? = 0.1 is about 308 S/cm and 1060 S/cm for unreduced and reduced samples respectively. The reduced conductivity of Zn0.476In1.032Ge0.476O3 is about 135 S/cm and for this composition samples are phase pure for new fluorite related phase. Thus, this study stresses the importance of cosubstitution to decrease amount of indium and understanding the various results for bulk samples.

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K. L. Chopra, S. Major, and D. K. Pandya, "Transparent conductors-A status review," Thin Solid Films, vol. 102, pp. 1- 46, 1983.

H. Ohta and H. Hosono, Mater. Today, vol. JUNE, p. 42, 2004.

H. Kawazoe, H. Yanagi, K. Ueda, and H. Hosono, "Transparent p-Type Conducting Oxides: Design and Fabrication of p-n Heterojunctions," MRS Bulletin, vol. 25, pp. 28-36, 2011.

G. Frank and H. Köstlin, "Electrical properties and defect model of tin-doped indium oxide layers," Applied Physics A, vol. 27, pp. 197-206, April 01 1982.

A. Ambrosini, A. Duarte, K. R. Poeppelmeier, M. Lane, C. R. Kannewurf, and T. O. Mason, "Electrical, Optical, and Structural Properties of Tin-Doped In2O3–M2O3 Solid Solutions (M=Y, Sc)," Journal of Solid State Chemistry, vol. 153, pp. 41-47, 2000/08/01/ 2000.

A. J. Freeman, K. R. Poeppelmeier, T. O. Mason, R. P. H. Chang, and T. J. Marks, "Chemical and thin-film strategies for new transparent conducting oxides," MRS Bulletin, vol. 25, pp. 45-51, 2000.

D. Bérardan, E. Guilmeau, A. Maignan, and B. Raveau, "In2 O3:Ge, a promising n-type thermoelectric oxide composite," Solid State Communications, vol. 146, pp. 97-101, 2008.

B. Cheng, H. Fang, J. Lan, Y. Liu, Y. H. Lin, and C. W. Nan, "Thermoelectric performance of Zn and Ge Co-Doped In2O 3 fine-grained ceramics by the spark plasma sintering," Journal of the American Ceramic Society, vol. 94, pp. 2279-2281, 2011.

M. Marezio, "Refinement of the crystal structure of In2O3 at two wavelengths," Acta Crystallogr., vol. 20, pp. 723-728, 1966.

V. M. Goldschmidt, T. Barth, and G. Lunde, "Isomorphie und Polymorphie der Sesquioxyde. Die Lanthaniden- Kontraktion und ihre Konsequenzen," Skr. Nor. Vidensk.-Akad.: Mat. - Naturvidensk. Kl., vol. 7, pp. 1-59, 1925.

S. C. Abrahams and J. L. Bernstein, "Remeasurement of the structure of hexagonal ZnO," Acta Crystallographica Section B, vol. 25, pp. 1233-1236, 1969.

G. B. Palmer, K. R. Poeppelmeier, and T. O. Mason, "Conductivity and transparency of ZnO/SnO2-cosubstituted In2O3," Chemistry of Materials, vol. 9, pp. 3121-3126, Dec 1997.

S. P. Harvey, K. R. Poeppelmeier, and T. O. Mason, "Subsolidus phase relationships in the ZnO-In2O 3-SnO2 system," Journal of the American Ceramic Society, vol. 91, pp. 3683-3689, 2008.

D. S. McLachlan, M. Blaszkiewicz, and R. E. Newnham, "Electrical Resistivity of Composites," Journal of the American Ceramic Society, vol. 73, pp. 2187-2203, 1990.

F. M. Smits, "Measurement of sheet resistivities with the four-point probe," The Bell System Technical Journal, vol. 37, pp. 711-718, 1958.

D. D. Edwards, T. O. Mason, F. Goutenoire, and K. R. Poeppelmeier, "A new transparent conducting oxide in the Ga2O3-In2O3-SnO2 system," Applied Physics Letters, vol. 70, pp. 1706-1708, 1997.

K. Rickert, N. Sedefoglu, S. Malo, V. Caignaert, H. Kavak, and K. R. Poeppelmeier, "Structural, Electrical, and Optical Properties of the Tetragonal, Fluorite-Related Zn0.456In1.084G e0.460O3," Chemistry of Materials, vol. 27, pp. 5072- 5079, 2015.

J. G. M. van Berkum, G. J. M. Sprong, T. H. de Keijser, R. Delhez, and E. J. Sonneveld, "The optimum standard specimen for X-ray diffraction line-profile analysis," Powder Diffraction, vol. 10, pp. 129-139, 2013.

M. N. Fujii, Y. Ishikawa, R. Ishihara, J. v. d. Cingel, M. R. T. Mofrad, J. P. S. Bermundo, et al., "Nano-crystallization in ZnO-doped In2O3 thin films via excimer laser annealing for thin-film transistors," AIP Advances, vol. 6, p. 065216, 2016.

K. Rickert, J. Harris, N. Sedefoglu, H. Kavak, D. E. Ellis, and K. R. Poeppelmeier, "Site identity and importance in cosubstituted bixbyite In2O3," Crystals, vol. 7, 2017.

L. Bizo, J. Choisnet, and B. Raveau, "Coupled substitutions in In2O3: New transparent conductors In2- xM2x/3Sbx/3O3 (M = Cu, Zn)," Materials Research Bulletin, vol. 41, pp. 2232-2237, Dec 14 2006.

D. Berardan, E. Guilmeau, A. Maignan, and B. Raveau, "Enhancement of the thermoelectric performances of In(2)O(3) by the coupled substitution of M(2+)/Sn(4+) for In(3+)," Journal of Applied Physics, vol. 104, Sep 15 2008.

D. Berardan, E. Guilmeau, A. Maignan, and B. Raveau, "In2O3 : Ge, a promising n-type thermoelectric oxide composite," Solid State Communications, vol. 146, pp. 97-101, Apr 2008.

A. Dolgonos, K. Lam, K. R. Poeppelmeier, A. J. Freeman, and T. O. Mason, "Electronic and optical properties of Ga3−xIn5+xSn2O16: An experimental and theoretical study," Journal of Applied Physics, vol. 115, p. 013703, 2014.

P. Kubelka and F. Munk, "Ein Beitrag zur Optik der Farbanstriche," Z. Tech. Phys., vol. 12, pp. 593-601, 1931.

J. Tauc, "Optical properties and electronic structure of amorphous Ge and Si," Materials Research Bulletin, vol. 3, pp. 37-46, 1968.

R. L. Weiher and R. P. Ley, "Optical Properties of Indium Oxide," Journal of Applied Physics, vol. 37, pp. 299-302, 1966.

J. Choisnet, L. Bizo, R. Retoux, and B. Raveau, "Antimony and antimony-tin doped indium oxide, IAO and IATO: Promising transparent conductors," Solid State Sciences, vol. 6, pp. 1121-1123, 2004.