Hostname: page-component-586b7cd67f-t7czq Total loading time: 0 Render date: 2024-11-28T06:13:59.375Z Has data issue: false hasContentIssue false
  • English
  • Français

Transport and surface conductivity in ZnO

Published online by Cambridge University Press:  22 May 2012

Craig H. Swartz
Craig H. Swartz*
Affiliation:
Materials Science, Engineering, and Commercialization Program, Texas State University, San Marcos, Texas 78666
*
a)Address all correspondence to this author. e-mail: [email protected]
Get access

Abstract

Control of the electrical properties of ZnO is difficult to achieve. Doping is affected by the presence of a n-type background. Magnetotransport measurements can extract detailed information on donors and acceptors, but characterization is complicated by effects such as the surface conductivity. This conducting layer can be activated by ambient illumination or by heating in the absence of oxygen. There are considerable differences in the behavior of the various polar and nonpolar crystal faces. This paper provides an overview of the properties of ZnO surface conductivity, as well as the methods which have been implemented to account for it while interpreting carrier transport measurements.

Type
Reviews
Information
Journal of Materials Research , Volume 27 , Issue 17: Focus Issue: Oxide Semiconductors , 14 September 2012 , pp. 2205 - 2213
Copyright
Copyright © Materials Research Society 2012

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1.Özgür, Ü., Hofstetter, D., and Morkoç, H.: ZnO devices and applications: A review of current status and future prospects. Proc. IEEE 98, 1255 (2010).CrossRefGoogle Scholar
2.Özgür, Ü., Alivov, Y.I., Liu, C., Teke, A., Reshchikov, M.A., Doğan, S., Avrutin, V., Cho, S-J., and Morkoç, H.: A comprehensive review of ZnO materials and devices. J. Appl. Phys. 98, 041301 (2005).CrossRefGoogle Scholar
3.Look, D.C.: Progress in ZnO materials and devices. J. Electron. Mater. 35, 1299 (2006).CrossRefGoogle Scholar
4.Janotti, A. and Van de Walle, C.G.: Fundamentals of zinc oxide as a semiconductor. Rep. Prog. Phys. 72, 126501 (2009).CrossRefGoogle Scholar
5.Pearton, S.J., Norton, D.P., Ip, K., Heo, Y.W., and Steiner, T.: Recent progress in processing and properties of ZnO. Prog. Mater. Sci. 50, 293 (2005).CrossRefGoogle Scholar
6.Avrutin, V., Silversmith, D.J., and Morkoç, H.: Doping asymmetry problem in ZnO: Current status and outlook. Proc. IEEE 98, 1269 (2010).CrossRefGoogle Scholar
7.Choi, Y-S., Kang, J-W., Hwang, D-K., and Park, S-J.: Recent advances in ZnO-based light-emitting diodes. IEEE Trans. Electron Devices 57, 26 (2010).CrossRefGoogle Scholar
8.Schmidt, O., Kiesel, P., Van de Walle, C.G., Johnson, N.M., Nause, J., and Döhler, G.H.: Effects of an electrically conducting layer at the zinc oxide surface. Jpn. J. Appl. Phys. 44, 7271 (2005).CrossRefGoogle Scholar
9.Collins, R.J. and Thomas, D.G.: Photoconduction and surface effects with zinc oxide crystals. Phys. Rev. 112, 388 (1958).CrossRefGoogle Scholar
10.Shapira, Y., Cox, S.M., and Lichtman, D.: Photodesorption from powdered zinc oxide. Surf. Sci. 50, 503 (1975).CrossRefGoogle Scholar
11.Göpel, W. and Lampe, U.: Influence of defects on the electronic structure of zinc oxide surfaces. Phys. Rev. B: Condens. Matter 22, 6447 (1980).CrossRefGoogle Scholar
12.Markevich, I.V., Kushnirenko, V.I., Borkovska, L.V., and Bulakh, B.M.: Mechanism of formation of highly conductive layer on ZnO crystal surface. Solid State Commun. 136, 475 (2005).CrossRefGoogle Scholar
13.Look, D.C.: Donors and acceptors in bulk ZnO grown by the hydrothermal, vapor-phase, and melt processes, in Zinc Oxide and Related Materials, edited by Christen, J., Jagadish, C., Look, D.C., Yao, T., and Bertram, F. (Mater. Res. Soc. Symp. Proc. 957, Warrendale, PA, 2007) p. 127. 0957-K08-05.Google Scholar
14.Look, D.C., Mosbacker, H.L., Strzhemechny, Y.M., and Brillson, L.J.: Effects of surface conduction on Hall-effect measurements in ZnO. Superlattices Microstruct. 38, 406 (2005).CrossRefGoogle Scholar
15.Look, D.C., Claflin, B., and Smith, H.E.: Origin of conductive surface layer in annealed ZnO. Appl. Phys. Lett. 92, 122108 (2008).CrossRefGoogle Scholar
16.Markevich, I.V., Kushnirenko, V.I., and Bulakh, B.M.: Photo-induced changes of photoconductivity and exciton luminescence in ZnO crystals. Phys. Status Solidi B 244, 1549 (2007).CrossRefGoogle Scholar
17.Rose, A.: Concepts in Photoconductivity and Allied Problems (John Wiley & Sons, New York, 1963) p. 43.Google Scholar
18.Katoa, H., Sanoa, M., Miyamotoa, K., and Yao, T.: Polarity control of ZnO on c-plane sapphire by plasma-assisted MBE. J. Cryst. Growth 275, e2459 (2005).CrossRefGoogle Scholar
19.Heiland, G. and Kunstmann, P.: Polar surfaces of ZnO crystals. Surf. Sci. 13, 71 (1969).CrossRefGoogle Scholar
20.Wander, A., Schedin, F., Steadman, P., Norris, A., McGrath, R., Turner, T.S., Thornton, G., and Harrison, N.M.: Stability of polar oxide surfaces. Phys. Rev. Lett. 86, 3811 (2001).CrossRefGoogle ScholarPubMed
21.Kreese, G., Dulub, O., and Diebold, U.: Competing stabilization mechanism for the polar ZnO (0001)-Zn surface. Phys. Rev. B: Condens. Matter 68, 245409 (2003).CrossRefGoogle Scholar
22.Murphy, T.E., Moaazami, K., and Phillips, J.D.: Trap-related photoconductivity in ZnO epilayers. J. Electron. Mater. 35, 543 (2006).CrossRefGoogle Scholar
23.Wander, A. and Harrison, N.M.: The stability of polar oxide surfaces: The interaction of H2O with ZnO(0001) and ZnO(000-1). J. Chem. Phys. 115, 2313 (2001).CrossRefGoogle Scholar
24.Yamamoto, A., Moriwaki, Y., Hattori, K., and Yanagi, H.: A comparative study of photoluminescence of Zn-polar and O-polar faces in single crystal ZnO using moment analysis. Appl. Phys. Lett. 98, 061907 (2011).CrossRefGoogle Scholar
25.Chevtchenko, S.A., Moore, J.C., Özgür, Ü., Gu, X., Baski, A.A., and Morkoç, H.: Comparative study of the (0001) and (000-1) surfaces of ZnO. Appl. Phys. Lett. 89, 182111 (2006).CrossRefGoogle Scholar
26.Allen, M.W., Swartz, C.H., Myers, T.H., Veal, T.D., McConville, C.F., and Durbin, S.M.: Bulk transport measurements in ZnO: The effect of surface electron layers. Phys. Rev. B: Condens. Matter 81, 075211 (2010).CrossRefGoogle Scholar
27.Schmeits, M.: Electrical conduction in semiconductor junctions with interface dipole layers. J. Appl. Phys. 80, 15 (1996).CrossRefGoogle Scholar
28.Allen, M.W., Miller, P., Reeves, R.J., and Durbin, S.M.: Influence of spontaneous polarization on the electrical and optical properties of bulk, single crystal ZnO. Appl. Phys. Lett. 90, 062104 (2007).CrossRefGoogle Scholar
29.Allen, M.W., Mendelsberg, R.J., Reeves, R.J., and Durbin, S.M.: Oxidized noble metal Schottky contacts to n-type ZnO. Appl. Phys. Lett. 94, 103508 (2009).CrossRefGoogle Scholar
30.Krusemeyer, H.J.: Surface potential, field effect mobility, and surface conductivity of ZnO crystals. Phys. Rev. 114, 655 (1959).CrossRefGoogle Scholar
31.Polyakov, A.Y., Smirnov, N.B., Govorkov, A.V., Belogorokhov, A.I., Kozhukhova, E.A., Markov, A.V., Osinsky, A., Dong, J.W., and Pearton, S.J.: Persistent photoconductivity in p-type ZnO(N) grown by molecular beam epitaxy. Appl. Phys. Lett. 90, 132103 (2007).CrossRefGoogle Scholar
32.Claflin, B., Look, D.C., Park, S.J., and Cantwell, G.: Persistent n-type photoconductivity in p-type ZnO. J. Cryst. Growth 287, 16 (2006).CrossRefGoogle Scholar
33.Schirmer, O.F. and Zwingel, D.: The yellow luminescence of zinc oxide. Solid State Commun. 8, 1559 (1970).CrossRefGoogle Scholar
34.Lopatiuk, O., Chernyaka, L., Osinsky, A., and Xie, J.Q.: Lithium-related states as deep electron traps in ZnO. Appl. Phys. Lett. 87, 214110 (2005).CrossRefGoogle Scholar
35.Barzola-Quiquia, J., Esquinazi, P., Villafuerte, M., Heluani, S.P., Pöppl, A., and Eisinger, K.: Origin of the giant negative photoresistance of ZnO single crystals. J. Appl. Phys. 108, 073530 (2010).CrossRefGoogle Scholar
36.Schmidt, O., Kiesel, P., Ehrentraut, D., Fukuda, T., and Johnson, N.M.: Electrical characterization of ZnO, including analysis of surface conductivity. Appl. Phys. A 88, 71 (2007).CrossRefGoogle Scholar
37.Look, D.C., Farlow, G.C., Reunchan, P., Limpijumnong, S., Zhang, S.B., and Nordlund, K.: Evidence for native-defect donors in n-type ZnO. Phys. Rev. Lett. 95, 225502 (2005).CrossRefGoogle ScholarPubMed
38.Janotti, A. and Van de Walle, C.G.: Hydrogen multicentre bonds. Nat. Mater. 6, 44 (2007).CrossRefGoogle ScholarPubMed
39.Nickel, N.H.: Hydrogen transport properties in zinc oxide. Superlattices Microstruct. 42, 3 (2007).CrossRefGoogle Scholar
40.Losurdo, M. and Giangregorio, M.M.. Interaction of atomic hydrogen with Zn-polar and O-polar ZnO surfaces. Appl. Phys. Lett. 86, 091901 (2005).CrossRefGoogle Scholar
41.Look, D.: Electrical Characterization of GaAs Materials and Devices (John Wiley & Sons, Edmunds, UK, 1989) p. 55ff.Google Scholar
42.Gelmont, B.L., Shur, M., and Stroscio, M.: Polar optical-phonon scattering in three- and two-dimensional electron gases. J. Appl. Phys. 77, 15 (1995).CrossRefGoogle Scholar
43.Rode, D.L.: Semiconductors and Semimetals (Academic Press, 10, New York, 1975) p. 84.Google Scholar
44.Ashkenov, N., Mbenkum, B.N., Bundesmann, C., Riede, V., Lorenz, M., Spemann, D., Kaidashev, E.M., Kasic, A., Schubert, M., Grundmann, M., Wagner, G., Neumann, H., Darakchieva, V., Arwin, H., and Monemar, B.: Infrared dielectric functions and phonon modes of high-quality ZnO films. J. Appl. Phys. 93, 126 (2003).CrossRefGoogle Scholar
45.Yang, X. and Giles, N.C.: Hall effect analysis of bulk ZnO comparing different crystal growth techniques. J. Appl. Phys. 105, 063709 (2009).CrossRefGoogle Scholar
46.Cattia, M., Noelb, Y., and Dovesi, R.: Full piezoelectric tensors of wurtzite and zinc blende ZnO and ZnS by first-principles calculations. J. Phys. Chem. Solids 64, 2183 (2003).CrossRefGoogle Scholar
47.Shokhovets, S., Gobsch, G., and Ambacher, O.: Conduction band parameters of ZnO. Superlattices Microstruct. 39, 299 (2006).CrossRefGoogle Scholar
48.Singh, J.: Electronic and Optoelectronic Properties of Semiconductor Structures (Cambridge University Press, Cambridge, UK, 2003) pp. 187–243.CrossRefGoogle Scholar
49.Chen, S.J., Liu, Y.C., Shao, C.L., Xu, C.S., Liu, Y.X., Wang, L., Liu, B.B., and Zou, G.T.: Reduction of the transverse effective charge of optical phonons in ZnO under pressure. Appl. Phys. Lett. 96, 231906 (2010).Google Scholar
50.Janotti, A. and Van de Walle, C.G.: Absolute deformation potentials and band alignment of wurtzite ZnO, MgO, and CdO. Phys. Rev. B: Condens. Matter 75, 121201 (2007).CrossRefGoogle Scholar
51.Look, D.C., Reynolds, D.C., Sizelove, J.R., Jones, R.L., Litton, C.W., Cantwell, G., and Harsch, W.C.: Electrical properties of bulk ZnO. Solid State Commun. 105, 399 (1998).CrossRefGoogle Scholar
52.Yang, X., Xu, C., and Giles, N.C.: Intrinsic electron mobilities in CdSe, CdS, ZnO, and ZnS and their use in analysis of temperature-dependent Hall measurements. J. Appl. Phys. 104, 073727 (2008).CrossRefGoogle Scholar
53.Hutson, A.R.: Hall effect studies of doped zinc oxide single crystals. Phys. Rev. 108, 222 (1957).CrossRefGoogle Scholar
54.Rode, D.L.: Semiconductors and Semimetals (Academic Press, 10, New York, 1975) p. 19.Google Scholar
55.Bertazzi, F., Bellotti, E., Furno, E., and Goano, M.: Experimental electron mobility in ZnO: A reassessment through Monte Carlo simulation. J. Electron. Mater. 38, 1677 (2009).CrossRefGoogle Scholar
56.Look, D.C. and Sizelove, J.R.: Dislocation scattering in GaN. Phys. Rev. Lett. 82, 1237 (1999).CrossRefGoogle Scholar
57.Sun, J.W., Lu, Y.M., Liu, Y.C., Shen, D.Z., Zhang, Z.Z., Li, B.H., Zhang, J.Y., Yao, B., Zhao, D.X., and Fan, X.W.: Hole transport in p-type ZnO films grown by plasma-assisted molecular beam epitaxy. Appl. Phys. Lett. 89, 232101 (2006).CrossRefGoogle Scholar
58.Look, D.C.: Quantitative analysis of surface donors in ZnO. Surf. Sci. 601, 5315 (2007).CrossRefGoogle Scholar
59.Bisotto, I., Granier, C., Brochen, S., Ribeaud, A., Ferret, P., Chicot, G., Rothman, J., Pernot, J., and Feuillet, G.: Residual doping in homoepitaxial zinc oxide layers grown by metal organic vapor phase epitaxy. Appl. Phys. Express 3, 095802 (2010).CrossRefGoogle Scholar
60.Yamaguchi, H., Komiyama, T., Chonan, Y., Ishidsuka, Y., Ito, R., and Aoyama, T.: Drift mobility of photocarriers on Zn- and O-polar surfaces of ZnO. Phys. Status Solidi C 7, 300 (2010).CrossRefGoogle Scholar
61.Tampo, H., Yamada, A., Fons, P., Shibata, H., Matsubara, K., Iwata, K., Nakahara, K., Takasu, H., and Niki, S.: Degenerate layers in epitaxial ZnO films grown on sapphire substrates. Appl. Phys. Lett. 84, 4413 (2004).CrossRefGoogle Scholar
62.Petukhov, V., Stoemenos, J., Rothman, J., Bakin, A., and Waag, A.: Interpretation of transport measurements in ZnO-thin films. Appl. Phys. A 102, 161 (2011).CrossRefGoogle Scholar
63.Look, D.C., Scott, R.C., Leedy, K.D., and Bayraktaroglu, B.: Donor and acceptor concentrations from a single mobility measurement in degenerate semiconductors: ZnO. Proc. SPIE Int. Soc. Opt. Eng. 7940, 794003 (2011).Google Scholar
64.Look, D.C., Leedy, K.D., Tomich, D.H., and Bayraktaroglu, B.: Mobility analysis of highly conducting thin films: Application to ZnO. Appl. Phys. Lett. 96, 062102 (2010).CrossRefGoogle Scholar
65.Look, D.C.: Electrical and optical properties of p-type ZnO. Semicond. Sci. Technol. 20, S55 (2005).CrossRefGoogle Scholar
66.Marfaing, Y. and Lusson, A.: Doping engineering of p-type ZnO. Superlattices Microstruct. 38, 385 (2005).CrossRefGoogle Scholar
67.Wolfe, C.M. and Stillman, G.E.: Anomalously high “mobility” in semiconductors. Appl. Phys. Lett. 18, 205 (1971).CrossRefGoogle Scholar
68.Bierwagen, O., Ive, T., Van de Walle, C.G., and Speck, J.S.: Causes of incorrect carrier-type identification in Van der Pauw Hall measurements. Appl. Phys. Lett. 93, 242108 (2008).CrossRefGoogle Scholar
69.Zhao, J-L., Li, X-M., Krtschil, A., Krost, A., Yu, W-D., Zhang, Y-W., Gu, Y-F., and Gao, X-D.: Study on anomalous high p-type conductivity in ZnO films on silicon substrate prepared by ultrasonic spray pyrolysis. Appl. Phys. Lett. 90, 062118 (2007).CrossRefGoogle Scholar
70.Lüa, J., Huang, K., Chen, X., Zhu, J., Meng, F., Song, X., and Sun, Z.: Enhanced photo-induced hydrophilicity of the sol–gel-derived ZnO thin films by Na-doping. Appl. Surf. Sci. 257, 2086 (2011).CrossRefGoogle Scholar