Skip to main content
SpringerLink
Log in

Fast sputter deposition of MoOx/metal/MoOx transparent electrodes on glass and PET substrates

  • Ceramics
  • Published:
Journal of Materials Science Aims and scope Submit manuscript

Abstract

Dielectric/metal/dielectric (DMD) transparent electrodes emerged as a compelling alternative to the widely used indium-tin-oxide (ITO) for solar cells and optoelectronic devices. DMD electrodes are especially attractive for flexible substrates, as, in contrast to ITO, they retain their low electrical resistance upon substrate bending and they do not require deposition at elevated temperatures. In a DMD, the choice of the dielectric is mainly dictated by the device architecture. Owing to its high work function, MoO3 is a commonly used hole-selective dielectric layer. The present work investigates MoOx/metal/MoOx (with 2 < x < 3) DMD electrodes, with Ag and Au as metals, fabricated by direct current, magnetron sputtering, at industry-relevant, high deposition rates. This was possible with a properly engineered MoOx target, providing high electrical conductivity and compactness. The sputtered electrodes on polyethylene terephthalate (PET) substrates show higher figure-of-merit than similar, evaporated electrodes in the literature. It is shown that the DMD electrodes with amorphous MoOx layers have low stability in water, but they are stable to other solvents, such as toluene, dimethylsulfoxide (DMSO), dimethylformamide (DMF), chlorobenzene or chloroform, allowing their implementation in devices like organic light-emitting diodes or perovskite solar cells. Further, it is shown that the electrodes show dramatically enhanced mechanical stability compared to ITO, when subjected to tensile bending tests.

Graphical abstract

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Figure 9
Figure 10
Figure 11
Figure 12
Figure 13
Figure 14
Figure 15

Similar content being viewed by others

References

  1. Brabec CJ, Scherf U, Dyakonov V (2014) Organic photovoltaics: materials, device physics, and manufacturing technologies, 2nd edn. Wiley-VCH-Verl, Weinheim

    Book  Google Scholar 

  2. Zilberberg K, Riedl T (2016) Metal-nanostructures–a modern and powerful platform to create transparent electrodes for thin-film photovoltaics. J Mater Chem A 4:14481–14508. https://doi.org/10.1039/C6TA05286J

    Article  CAS  Google Scholar 

  3. Lewis J, Grego S, Chalamala B et al (2004) Highly flexible transparent electrodes for organic light-emitting diode-based displays. Appl Phys Lett 85:3450–3452. https://doi.org/10.1063/1.1806559

    Article  CAS  Google Scholar 

  4. Guillén C, Herrero J (2011) TCO/metal/TCO structures for energy and flexible electronics. Thin Solid Films 520:1–17. https://doi.org/10.1016/j.tsf.2011.06.091

    Article  CAS  Google Scholar 

  5. Dimopoulos T, Bauch M, Wibowo RA et al (2015) Properties of transparent and conductive Al:ZnO/Au/Al:ZnO multilayers on flexible PET substrates. Mater Sci Eng B 200:84–92. https://doi.org/10.1016/j.mseb.2015.06.008

    Article  CAS  Google Scholar 

  6. Szczyrbowski J, Dietrich A, Hartig K (1989) Bendable silver-based low emissivity coating on glass. Sol Energy Mater 19:43–53. https://doi.org/10.1016/0165-1633(89)90022-1

    Article  CAS  Google Scholar 

  7. Szczyrbowski J, Bräuer G, Ruske M et al (1999) New low emissivity coating based on TwinMag® sputtered TiO2 and Si3N4 layers. Thin Solid Films 351:254–259. https://doi.org/10.1016/S0040-6090(99)00086-3

    Article  CAS  Google Scholar 

  8. Lee MH, Choi WH, Zhu F (2016) Solution-processable organic-inorganic hybrid hole injection layer for high efficiency phosphorescent organic light-emitting diodes. Opt Express 24:A592. https://doi.org/10.1364/OE.24.00A592

    Article  CAS  Google Scholar 

  9. Fan X, Cui C, Fang G et al (2012) Efficient Polymer Solar Cells Based on Poly(3-hexylthiophene):Indene-C70 Bisadduct with a MoO3 Buffer Layer. Adv Funct Mater 22:585–590. https://doi.org/10.1002/adfm.201102054

    Article  CAS  Google Scholar 

  10. Hou F, Su Z, Jin F et al (2015) Efficient and stable planar heterojunction perovskite solar cells with an MoO3/PEDOT:PSS hole transporting layer. Nanoscale 7:9427–9432. https://doi.org/10.1039/C5NR01864A

    Article  CAS  Google Scholar 

  11. Kinner L, Hermerschmidt F, Dimopoulos T, List-Kratochvil EJW (2020) Implementation of flexible embedded nanowire electrodes in organic light-emitting diodes. Phys Status Solidi RRL–Rapid Res Lett 14:2000305. https://doi.org/10.1002/pssr.202000305

    Article  CAS  Google Scholar 

  12. Gong Y, Dong Y, Zhao B et al (2020) Diverse applications of MoO3 for high performance organic photovoltaics: fundamentals, processes and optimization strategies. J Mater Chem A 8:978–1009. https://doi.org/10.1039/C9TA12005J

    Article  CAS  Google Scholar 

  13. Meyer J (2011) Electronic structure of molybdenum-oxide films and associated charge injection mechanisms in organic devices. J Photonics Energy 1:011109. https://doi.org/10.1117/1.3555081

    Article  CAS  Google Scholar 

  14. Battaglia C, Yin X, Zheng M et al (2014) Hole Selective MoOx Contact for Silicon Solar Cells. Nano Lett 14:967–971. https://doi.org/10.1021/nl404389u

    Article  CAS  Google Scholar 

  15. Thibau ES, Llanos A, Lu Z-H (2017) Disruptive and reactive interface formation of molybdenum trioxide on organometal trihalide perovskite. Appl Phys Lett 110:081604. https://doi.org/10.1063/1.4976697

    Article  CAS  Google Scholar 

  16. Cauduro F, dos Reis AL, Chen R et al (2017) Crystalline molybdenum oxide thin-films for application as interfacial layers in optoelectronic devices. ACS Appl Mater Interfaces 9:7717–7724. https://doi.org/10.1021/acsami.6b14228

    Article  CAS  Google Scholar 

  17. Carcia PF, McCarron EM (1987) Synthesis and properties of thin film polymorphs of molybdenum trioxide. Thin Solid Films 155:53–63. https://doi.org/10.1016/0040-6090(87)90452-4

    Article  CAS  Google Scholar 

  18. Dukstiene N, Sinkeviciute D, Guobiene A (2012) Morphological, structural and optical properties of MoO2 films electrodeposited on SnO2∣glass plate. Open Chem 10:1106–1118. https://doi.org/10.2478/s11532-012-0012-7

    Article  CAS  Google Scholar 

  19. Moosburger-Will J, Kündel J, Klemm M et al (2009) Fermi surface of MoO2 studied by angle-resolved photoemission spectroscopy, de Haas–van Alphen measurements, and electronic structure calculations. Phys Rev B 79:115113. https://doi.org/10.1103/PhysRevB.79.115113

    Article  CAS  Google Scholar 

  20. Inzani K, Nematollahi M, Vullum-Bruer F et al (2017) Electronic properties of reduced molybdenum oxides. Phys Chem Chem Phys 19:9232–9245. https://doi.org/10.1039/C7CP00644F

    Article  CAS  Google Scholar 

  21. de Castro IA, Datta RS, Ou JZ et al (2017) Molybdenum oxides-from fundamentals to functionality. Adv Mater 29:1701619. https://doi.org/10.1002/adma.201701619

    Article  CAS  Google Scholar 

  22. Scanlon DO, Watson GW, Payne DJ et al (2010) Theoretical and experimental study of the electronic structures of MoO3 and MoO2. J Phys Chem C 114:4636–4645. https://doi.org/10.1021/jp9093172

    Article  CAS  Google Scholar 

  23. Shafaei S, Van Opdenbosch D, Fey T et al (2016) Enhancement of the antimicrobial properties of orthorhombic molybdenum trioxide by thermal induced fracturing of the hydrates. Mater Sci Eng C 58:1064–1070. https://doi.org/10.1016/j.msec.2015.09.069

    Article  CAS  Google Scholar 

  24. Rempel KU, Williams-Jones AE, Migdisov AA (2008) The solubility of molybdenum dioxide and trioxide in HCl-bearing water vapour at 350 °C and pressures up to 160 bars. Geochim Cosmochim Acta 72:3074–3083. https://doi.org/10.1016/j.gca.2008.04.015

    Article  CAS  Google Scholar 

  25. Maniruzzaman Md, Lim CH, Yang K et al (2014) Indium Tin Oxide-free PEDOT:PSS/SAM/MoO3/Au/MoO3 multilayer electrodes for organic solar cells. J Nanosci Nanotechnol 14:7779–7783. https://doi.org/10.1166/jnn.2014.9454

    Article  CAS  Google Scholar 

  26. Bullock J, Wan Y, Xu Z et al (2018) Stable dopant-free asymmetric heterocontact silicon solar cells with efficiencies above 20%. ACS Energy Lett 3:508–513. https://doi.org/10.1021/acsenergylett.7b01279

    Article  CAS  Google Scholar 

  27. Nguyen D-T, Vedraine S, Cattin L et al (2012) Effect of the thickness of the MoO3 layers on optical properties of MoO3 /Ag/MoO3 multilayer structures. J Appl Phys 112:063505. https://doi.org/10.1063/1.4751334

    Article  CAS  Google Scholar 

  28. Cattin L, Lare Y, Makha M et al (2013) Effect of the Ag deposition rate on the properties of conductive transparent MoO3/Ag/MoO3 multilayers. Sol Energy Mater Sol Cells 117:103–109. https://doi.org/10.1016/j.solmat.2013.05.026

    Article  CAS  Google Scholar 

  29. Akdemir O, Zolfaghari Borra M, Nasser H et al (2020) MoOx/Ag/MoOx multilayers as hole transport transparent conductive electrodes for n-type crystalline silicon solar cells. Int J Energy Res 44:3098–3109. https://doi.org/10.1002/er.5145

    Article  CAS  Google Scholar 

  30. Abachi T, Cattin L, Louarn G et al (2013) Highly flexible, conductive and transparent MoO3/Ag/MoO3 multilayer electrode for organic photovoltaic cells. Thin Solid Films 545:438–444. https://doi.org/10.1016/j.tsf.2013.07.048

    Article  CAS  Google Scholar 

  31. Boehm AM, Wieser J, Butrouna K, Graham KR (2017) A new photon source for ultraviolet photoelectron spectroscopy of organic and other damage-prone materials. Org Electron 41:9–16. https://doi.org/10.1016/j.orgel.2016.11.032

    Article  CAS  Google Scholar 

  32. Miyata N, Akiyoshi S (1985) Preparation and electrochromic properties of rf-sputtered molybdenum oxide films. J Appl Phys 58:1651–1655. https://doi.org/10.1063/1.336307

    Article  CAS  Google Scholar 

  33. Fernandes Cauduro AL, Fabrim ZE, Ahmadpour M et al (2015) Tuning the optoelectronic properties of amorphous MoOx films by reactive sputtering. Appl Phys Lett 106:202101. https://doi.org/10.1063/1.4921367

    Article  CAS  Google Scholar 

  34. Mehmood H, Bektaş G, Yıldız İ et al (2019) Electrical, optical and surface characterization of reactive RF magnetron sputtered molybdenum oxide films for solar cell applications. Mater Sci Semicond Process 101:46–56. https://doi.org/10.1016/j.mssp.2019.05.018

    Article  CAS  Google Scholar 

  35. Tauc J (1968) Optical properties and electronic structure of amorphous Ge and Si. Mater Res Bull 3:37–46. https://doi.org/10.1016/0025-5408(68)90023-8

    Article  CAS  Google Scholar 

  36. Peelaers H, Chabinyc ML, Van de Walle CG (2017) Controlling n-type doping in MoO3. Chem Mater 29:2563–2567. https://doi.org/10.1021/acs.chemmater.6b04479

    Article  CAS  Google Scholar 

  37. Vos MFJ, Macco B, Thissen NFW et al (2016) Atomic layer deposition of molybdenum oxide from (NtBu )2 (NMe2) 2 Mo and O2 plasma. J Vac Sci Technol Vac Surf Films 34:01A103. https://doi.org/10.1116/1.4930161

    Article  CAS  Google Scholar 

  38. Vasilopoulou M, Douvas AM, Georgiadou DG et al (2012) The influence of hydrogenation and oxygen vacancies on molybdenum oxides work function and gap states for application in organic optoelectronics. J Am Chem Soc 134:16178–16187. https://doi.org/10.1021/ja3026906

    Article  CAS  Google Scholar 

  39. Rakić AD, Djurišić AB, Elazar JM, Majewski ML (1998) Optical properties of metallic films for vertical-cavity optoelectronic devices. Appl Opt 37:5271. https://doi.org/10.1364/AO.37.005271

    Article  Google Scholar 

  40. Johnson PB, Christy RW (1972) Optical constants of the noble metals. Phys Rev B 6:4370–4379. https://doi.org/10.1103/PhysRevB.6.4370

    Article  CAS  Google Scholar 

  41. Haacke G (1976) New figure of merit for transparent conductors. J Appl Phys 47:4086–4089. https://doi.org/10.1063/1.323240

    Article  CAS  Google Scholar 

  42. Ebner D, Bauch M, Dimopoulos T (2017) High performance and low cost transparent electrodes based on ultrathin Cu layer. Opt Express 25:A240–A252

    Article  CAS  Google Scholar 

  43. Anwar M, Hogarth CA, Bulpett R (1989) Effect of substrate temperature and film thickness on the surface structure of some thin amorphous films of MoO3 studied by X-ray photoelectron spectroscopy (ESCA). J Mater Sci 24:3087–3090. https://doi.org/10.1007/BF01139023

    Article  CAS  Google Scholar 

  44. Yordanov R, Boyadjiev S, Georgieva V, Vergov L (2014) Characterization of thin MoO3 films formed by RF and DC-magnetron reactive sputtering for gas sensor applications. J Phys Conf Ser 514:012040. https://doi.org/10.1088/1742-6596/514/1/012040

    Article  CAS  Google Scholar 

  45. Bihn J-H, Park J, Kang Y-C (2011) Synthesis and characterization of Mo films deposited by RF sputtering at various oxygen ratios. J Korean Phys Soc 58:509–514. https://doi.org/10.3938/jkps.58.509

    Article  CAS  Google Scholar 

  46. Kohlrausch F (1996) Praktische Physik. Vieweg+Teubner Verlag, Wiesbaden

    Book  Google Scholar 

  47. Jaritz M, Behm H, Hopmann C et al (2017) The effect of UV radiation from oxygen and argon plasma on the adhesion of organosilicon coatings on polypropylene. J Phys Appl Phys 50:015201. https://doi.org/10.1088/1361-6463/50/1/015201

    Article  CAS  Google Scholar 

  48. Chiba K, Nakatani K (1984) Photoenhance migration of silver atoms in transparent heat mirror coatings. Thin Solid Films 112:359–367. https://doi.org/10.1016/0040-6090(84)90463-2

    Article  CAS  Google Scholar 

  49. Cattin L, Jouad E, Stephant N et al (2017) Dielectric/metal/dielectric alternative transparent electrode: observations on stability/degradation. J Phys Appl Phys 50:375502. https://doi.org/10.1088/1361-6463/aa7dfd

    Article  CAS  Google Scholar 

  50. Liao X, Jeong AR, Wilks RG et al (2019) Tunability of MoO3 thin-film properties due to annealing in situ monitored by hard x-ray photoemission. ACS Omega 4:10985–10990. https://doi.org/10.1021/acsomega.9b01027

    Article  CAS  Google Scholar 

  51. Griffin J, Watters DC, Yi H et al (2013) The influence of MoOx Anode stoicheometry on the performance of bulk heterojunction polymer solar cells. Adv Energy Mater 3:903–908. https://doi.org/10.1002/aenm.201200886

    Article  CAS  Google Scholar 

  52. Ahmadpour M, Fernandes Cauduro AL, Méthivier C et al (2019) Crystalline molybdenum oxide layers as efficient and stable hole contacts in organic photovoltaic devices. ACS Appl Energy Mater 2:420–427. https://doi.org/10.1021/acsaem.8b01452

    Article  CAS  Google Scholar 

  53. Haynes WM (2014) CRC handbook of chemistry and physics, p 4–77

  54. Sian TS, Reddy GB (2006) Effect of stoichiometry and microstructure on hydrolysis in MoO3 films. Chem Phys Lett 418:170–173. https://doi.org/10.1016/j.cplett.2005.10.112

    Article  CAS  Google Scholar 

  55. Maniruzzaman Md, Rahman MA, Jeong K et al (2014) ITO free MoO3/Au/MoO3 structures using Al2O3 as protective barrier between MoO3 and PEDOT:PSS in organic solar cells. Renew Energy 71:193–199. https://doi.org/10.1016/j.renene.2014.05.040

    Article  CAS  Google Scholar 

  56. Park S-I, Ahn J-H, Feng X et al (2008) Theoretical and experimental studies of bending of inorganic electronic materials on plastic substrates. Adv Funct Mater 18:2673–2684. https://doi.org/10.1002/adfm.200800306

    Article  CAS  Google Scholar 

Download references

Acknowledgement

TD, CL, EF and JW acknowledge financial support through the project NEXT-FOIL (Next generation conductive solar foil for flexible photovoltaics) under the umbrella of SOLAR-ERA.NET Cofund (FFG, SFOE). GL thanks Prof. N. Koch (Humboldt Universität zu Berlin) for granting access to the photoemission instrumentation. GL and ELK acknowledge the financial support of DFG (Projektnummer 182,087,777—SFB 951) and the HySPRINT Innovation Lab at Helmholtz-Zentrum Berlin (through the framework of the Joint Lab GEN_FAB).

Author information

Authors and Affiliations

  1. Center for Energy, Photovoltaic Systems, AIT Austrian Institute of Technology, Vienna, Austria

    Selina Goetz, Rachmat Adhi Wibowo, Martin Bauch, Neha Bansal & Theodoros Dimopoulos

  2. Institute of Applied Physics, Vienna University of Technology, Vienna, Austria

    Selina Goetz & Markus Valtiner

  3. Institut Für Physik, Institut Für Chemie, IRIS Adlershof, Humboldt-Universität zu Berlin, Berlin, Germany

    Giovanni Ligorio & Emil List-Kratochvil

  4. Helmholtz‐Zentrum Berlin für Materialien und Energie GmbH, Berlin, Germany

    Emil List-Kratochvil

  5. Plansee SE, Reutte, Austria

    Christian Linke, Enrico Franzke & Jörg Winkler

Authors
  1. Selina Goetz
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Rachmat Adhi Wibowo
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Martin Bauch
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Neha Bansal
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Giovanni Ligorio
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Emil List-Kratochvil
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. Christian Linke
    View author publications

    You can also search for this author in PubMed Google Scholar

  8. Enrico Franzke
    View author publications

    You can also search for this author in PubMed Google Scholar

  9. Jörg Winkler
    View author publications

    You can also search for this author in PubMed Google Scholar

  10. Markus Valtiner
    View author publications

    You can also search for this author in PubMed Google Scholar

  11. Theodoros Dimopoulos
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Theodoros Dimopoulos.

Ethics declarations

Conflicts of interest

The authors declare that they have no conflicts of interest.

Additional information

Handling Editor: David Cann.

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Goetz, S., Wibowo, R.A., Bauch, M. et al. Fast sputter deposition of MoOx/metal/MoOx transparent electrodes on glass and PET substrates. J Mater Sci 56, 9047–9064 (2021). https://doi.org/10.1007/s10853-021-05839-9

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10853-021-05839-9

Search

Navigation