Hostname: page-component-cd9895bd7-mkpzs Total loading time: 0 Render date: 2024-12-28T18:04:47.806Z Has data issue: false hasContentIssue false
  • English
  • Français

Optical properties of ZnO/Al/ZnO multilayer films for large area transparent electrodes

Published online by Cambridge University Press:  17 November 2014

Egidius Rutatizibwa Rwenyagila ,
Benjamin Agyei-Tuffour ,
Martiale Gaetan Zebaze Kana ,
Omololu Akin-Ojo  and
Winston Oluwole Soboyejo
Egidius Rutatizibwa Rwenyagila
Affiliation:
Department of Materials Science and Engineering, African University of Science and Technology (AUST), PMB 681, Garki, Abuja, Nigeria; and Physics Department, University of Dar es Salaam, Dar es Salaam 35063, Tanzania
Benjamin Agyei-Tuffour
Affiliation:
Department of Materials Science and Engineering, African University of Science and Technology (AUST), PMB 681, Garki, Abuja, Nigeria
Martiale Gaetan Zebaze Kana
Affiliation:
Physics Advanced Laboratory, Sheda Science and Technology Complex (SHESTCO), Abuja, Nigeria; and Department of Materials Science and Engineering, Kwara State University, PMB 1531, Malete, Nigeria
Omololu Akin-Ojo
Affiliation:
Department of Theoretical and Applied Physics, African University of Science and Technology (AUST), PMB 681, Garki, Abuja, Nigeria
Winston Oluwole Soboyejo*
Affiliation:
Department of Materials Science and Engineering, African University of Science and Technology (AUST), PMB 681, Garki, Abuja, Nigeria; and Department of Mechanical and Aerospace Engineering & the Princeton Institute of Science and Technology of Materials, Princeton University, New Jersey 08544, USA
*
a)Address all correspondence to this author. e-mail: [email protected]
Get access

Abstract

This study presents the optical properties of layered ZnO/Al/ZnO composite thin films that are being explored for potential applications in solar cells and light emitting devices. The composite thin films are explored as alternatives to ZnO thin films. They are produced via radio frequency magnetron sputtering. The study clarifies the role of the aluminum mid-layer in a ZnO (25 nm)/Al/ZnO (25 nm) film structure. Multilayers with low resistivity ∼362 µΩ cm and average transmittances between ∼85 and 90% (in the visible region of the solar spectrum) are produced. The highest Haacke figure of merit of 4.72 × 10−3 Ω−1 was obtained in a multilayer with mid-layer Al thickness of 8 nm. The combined optical band gap energy of the multilayered films increased by ∼0.60 eV for mid-layer Al thicknesses between ∼1 and 10 nm. The observed shifts in the optical absorption edges to shorter wave lengths of the spectrum are shown to be in agreement with the Moss–Burstein effect.

Keywords

conductivitymid-Almultilayertransmittance
Type
Articles
Information
Journal of Materials Research , Volume 29 , Issue 24 , 28 December 2014 , pp. 2912 - 2920
Copyright
Copyright © Materials Research Society 2014 

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

Chopra, K.L., Major, S., and Pandya, D.K.: Transparent conductors – A status review. Thin Solid Films 102, 1–46 (1983).Google Scholar
Pan, F., Gao, S., Chen, C., Song, C., and Zeng, F.: Recent progress in resistive random access memories: Materials, switching mechanisms, and performance. Mater. Sci. Eng., R 83, 1–59 (2014).CrossRefGoogle Scholar
Sivaramakrishnan, K. and Alford, T.L.: Conduction and transmission analysis in gold nanolayers embedded in zinc oxide for flexible electronics. Appl. Phys. Lett. 96, 201109 (2010).Google Scholar
Hadis, M. and Ümit, Ö.: ZnO Oxide Fundamentals, Materials and Device Technology (WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim, 2009).Google Scholar
Al-Kuhaili, M.F., Al-Maghrabi, M.A., Durrani, S.M.A., and Bakhtiari, I.A.: Investigation of ZnO/Al/ZnO multilayers as transparent conducting coatings. J. Phys. D: Appl. Phys. 41, 215302 (2008).CrossRefGoogle Scholar
Dhananjay, , Nagaraju, J., and Krupenidhi, S.B.: Off-centered polarization and ferroelectric phase transition in Li-doped ZnO thin films grown by pulsed-laser ablation. J. Appl. Phys. 101, 104104 (2007).CrossRefGoogle Scholar
Pearton, S.J., Norton, D.P., Heo, Y.W., and Steiner, T.: Recent progress in processing and properties of ZnO. Prog. Mater. Sci. 50, 293–340 (2005).CrossRefGoogle Scholar
Xudong, W., Jinhui, S., Jin, L., and Zhong, L.W.: Direct-current nanogenerator driven by ultrasonic waves. Science 316, 102 (2007).Google Scholar
Yang, C.Y., Song, C., Zeng, F., and Pan, F.: Giant piezoelectric d33 coefficient in ferroelectric vanadium doped ZnO films. Appl. Phys. Lett. 90, 242903 (2008).CrossRefGoogle Scholar
Yang, C.Y., Song, C., Zeng, F., and Pan, F.: V5+ ionic displacement induced ferroelectric behavior in V-doped ZnO films. Appl. Phys. Lett. 90, 242903 (2007).Google Scholar
Onodera, A., Tamaki, N., Kawamura, Y., Jin, S.T.K., and Yamashita, H.: Dielectric activity and ferroelectricity in piezoelectric semiconductor Li-doped ZnO. J. Appl. Phys. 35, 5160–5162 (1996).Google Scholar
Onodera, A., Tamaki, N., Jin, K., and Yamashita, H.: Ferroelectric properties in piezoelectric semiconductor Zn1-xMxO (M=Li, Mg). J. Appl. Phys. 36, 6008–6011 (1997).CrossRefGoogle Scholar
Song, D., Aberle, A.G., and Xia, J.: Optimisation of ZnO: Al films by change of sputter gas pressure for solar cell application. Appl. Surf. Sci. 195, 291–296 (2002).Google Scholar
Lin, S.S., Huang, J.L., and Lii, D.F.: Effect of substrate temperature on the properties of Ti-doped ZnO films by simultaneous RF and DC magnetron sputtering. Mater. Chem. Phys. 90, 22–30 (2005).CrossRefGoogle Scholar
Tsujinoa, J., Hommaa, N., Tomoaki, S., Isao, S., and Yoshihiko, A.: Preparation of Al-doped ZnO thin films by RF thermal plasma evaporation. Thin Solid Films 407, 86–91 (2002).CrossRefGoogle Scholar
Aktaruzzaman, A.F., Sharma, G.L., and Mahgotra, L.K.: Electrical, optical and annealing characteristics of ZnO: Al films prepared by spray pyrolysis. Thin Solid Films 198, 67–74 (1991).CrossRefGoogle Scholar
Nakada, T., Yukiyasu, O., Naoki, M., and Akio, K.: Transparent conducting boron-doped zinc oxide films deposited by DC-magnetron sputtering in B2H6-Ar mixture. Appl. Phys. 34, 3623–3627 (1995).Google Scholar
Gomez, H.A., Maldonado, J.P., Asomoza, R., Zironi, E.P., Canetas-Ortega, J., and Palacios-Gomez, J.: Characterization of indium-doped zinc oxide films deposited by pyrolytic spray with different indium compounds as dopants. Thin Solid Films 293, 117–123 (1997).Google Scholar
Tiburcio-Silver, A. and Avila-Garcia, A.: Properties of gallium-doped ZnO deposited onto glass by spray pyrolysis. Sol. Energy Mater. Sol. Cells 55, 3–10 (1998).Google Scholar
Park, S-H., Kim, H-M., Rhee, B-R., Ko, E-Y., and Shon, S-H.: Effects of oxygen concentration on characteristics of RF-sputtered In2O3-ZnO thin films. Jpn. J. Appl. Phys. 40, 1429–1430 (2001).Google Scholar
Sahu, D.R., Lin, S-Y., and Huang, J-L.: ZnO/Ag/ZnO multilayer films for the application of a very low resistance transparent electrode. Appl. Surf. Sci. 252, 7509–7514 (2006).CrossRefGoogle Scholar
Sahu, D.R. and Huang, J-L.: Design of ZnO/Ag/ZnO multilayer transparent conductive films. Mater. Sci. Eng., B 130, 295–299 (2006).Google Scholar
Ando, E. and Miyazaki, M.: Moisture resistance of the low-emissivity coatings with a layer structure of Al-doped ZnO/Ag/Al-doped ZnO. Thin Solid Films 392, 289–293 (2001).CrossRefGoogle Scholar
Bender, M., Seelig, W., Daube, C., Frankenberger, H., Ocker, B., and Stollenwerk, J.: Dependence of film composition and thicknesses on optical and electrical properties of ITO–metal–ITO multilayers. Thin Solid Films 326, 67–71 (1998).Google Scholar
Feltrin, A. and Freundlich, A.: Material considerations for terawatt level deployment of photovoltaics. Renewable Energy 33, 180–185 (2008).Google Scholar
Dhar, A. and Alford, T.L.: High quality transparent TiO2/Ag/TiO2 composite electrode films deposited on flexible substrate at room temperature by sputtering. APL Mater. 1, 012102 (2013).CrossRefGoogle Scholar
Choi, K.H., Kim, J.Y., Lee, Y.S., and Kim, H.J.: ITO/Ag/ITO multilayer films for the application of a very low resistance transparent electrode. Thin Solid Films 341, 152–155 (1999).Google Scholar
Klöppel, A., Kriegseis, W., Meyer, B.K., Scharmann, A., Daube, C., Stollenwerk, J., and Trube, J.: Dependence of the electrical and optical behaviour of ITO-silver-ITO multilayers on the silver properties. Thin Solid Films 365, 139–146 (2000).Google Scholar
Fahland, M., Karlsson, P., and Charton, C.: Low resistivity transparent electrodes for displays on polymer substrates. Thin Solid Films 392, 334–337 (2001).Google Scholar
Klöppel, A., Meyer, B., and Trube, J.: Influence of substrate temperature and sputtering atmosphere on electrical and optical properties of double silver layer systems. Thin Solid Films 392, 311–314 (2001).CrossRefGoogle Scholar
Sawada, M., Higuchi, M., Kondo, S., and Saka, H.: Characteristics of indium-tin-oxide/silver/indium-tin-oxide sandwich films and their application to simple liquid-crystal displays. Jpn. J. Appl. Phys. 40, 3332–3336 (2001).Google Scholar
Jung, Y.S., Choi, Y.W., Lee, H.C., and Lee, D.W.: Effects of thermal treatment on the electrical and optical properties of silver-based indium tin oxide/metal/indium tin oxide structures. Thin Solid Films 440, 278–284 (2003).CrossRefGoogle Scholar
Sahu, D.R. and Huang, J.L.: High quality transparent conductive ZnO/Ag/ZnO multilayer films deposited at room temperature. Thin Solid Films 515, 876–879 (2006).CrossRefGoogle Scholar
Sahu, D.R. and Huang, J.L.: Characteristics of ZnO-Cu-ZnO multilayer films on copper layer properties. Appl. Surf. Sci. 253, 827–832 (2006).Google Scholar
Sahu, D.R. and Huang, J.L.: Dependence of film thickness on the electrical and optical properties of ZnO-Cu-ZnO multilayers. Appl. Surf. Sci. 253, 915–918 (2006).Google Scholar
Halpern, A. and Erlbach, E.: Chapter 5: Simple electric circuits. In Theory and Problems of Beginning Physics II Waves, Electromagnetism, Optics and Modern Physics (McGraw-Hill, New York, NY, 1998), p. 141.Google Scholar
Sleepless Media: Current metal prices. Mining journal ICMJ (2009). [Online]. Available: http://www.icmj.com/current-metal-prices.php. [Accessed 7 March 2014].Google Scholar
Bai, S.N. and Tseng, T.Y.: Electrical and optical properties of ZnO: Al thin films grown by magnetron sputtering. J. Mater. Sci.: Mater. Electron. 20, 253–256 (2009).Google Scholar
Luka, G., Krajewski, T.A., Witkowski, B.S., Wisz, G., Virt, I.S., Guziewicz, E., and Godlewski, M.: Aluminum-doped zinc oxide films grown by atomic layer deposition for transparent electrode applications. J. Mater. Sci.: Mater. Electron. 22, 1810–1815 (2011).Google Scholar
Bouznit, Y., Beggah, Y., and Djessas, K.: RF magnetron sputtering of ZnO and Al-doped ZnO films from ceramic and nanopowder targets: A comparative study. J. Sol-Gel Sci. Technol. 61, 449–454 (2012).CrossRefGoogle Scholar
Burstein, E.: Anomalous optical absorption limit in InSb. Phys. Rev. 93, 632–633 (1954).Google Scholar
Bennett, J.M.: Polarization. In Hand Book of Optics: Fundamentals, Techniques and Design, 2nd ed. (McGraw-Hill, New York, NY, 1995), Vol. I, Chapter 5.Google Scholar
Chopra, K.L. and Bahl, S.K.: Structural, electrical and optical properties of amorphous germanium films. Phys. Rev. B 1, 2545–2556 (1970).CrossRefGoogle Scholar
Filippov, V.V. and Shulitskii, B.G.: Optical modeling and optimization of multilayer organic photovoltaic cells. J. Appl. Spectrosc. 77, 266–272 (2010).CrossRefGoogle Scholar
Khusayfan, N.M. and El-Nahass, M.M.: Study of structure and electro-optical characteristics of indium tin oxide thin films. Adv. Condens. Matter Phys. 2013, 5 (2013).Google Scholar