Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

High-mobility p-type semiconducting two-dimensional β-TeO2

An Author Correction to this article was published on 07 June 2021

This article has been updated


Wide-bandgap oxide semiconductors are essential for the development of high-speed and energy-efficient transparent electronics. However, while many high-mobility n-type oxide semiconductors are known, wide-bandgap p-type oxides have carrier mobilities that are one to two orders of magnitude lower due to strong carrier localization near their valence band edge. Here, we report the growth of bilayer beta tellurium dioxide (β-TeO2), which has recently been proposed theoretically as a high-mobility p-type semiconductor, through the surface oxidation of a eutectic mixture of tellurium and selenium. The isolated β-TeO2 nanosheets are transparent and have a direct bandgap of 3.7 eV. Field-effect transistors based on the nanosheets exhibit p-type switching with an on/off ratio exceeding 106 and a field-effect hole mobility of up to 232 cm2 V−1 s−1 at room temperature. A low effective mass of 0.51 was observed for holes, and the carrier mobility reached 6,000 cm2 V−1 s−1 on cooling to −50 °C.

This is a preview of subscription content, access via your institution

Relevant articles

Open Access articles citing this article.

Access options

Rent or buy this article

Get just this article for as long as you need it


Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Schematic of tellurium oxide synthesis and transfer.
Fig. 2: Characterization of the 2D TeO2.
Fig. 3: Electronic and optical characterization of the 2D β-TeO2.
Fig. 4: Field-effect transistor measurements of 2D β-TeO2.

Data availability

The data used to determine the data points shown within the plots presented in this paper, and other findings from this study, are available from the corresponding authors upon reasonable request.

Change history


  1. Thomas, G. Invisible circuits. Nature 389, 907–908 (1997).

    Article  Google Scholar 

  2. Nomura, K. et al. Room-temperature fabrication of transparent flexible thin-film transistors using amorphous oxide semiconductors. Nature 432, 488–492 (2004).

    Article  Google Scholar 

  3. Wager, J. F. Transparent electronics. Science 300, 1245–1246 (2003).

    Article  Google Scholar 

  4. Nomura, K. et al. Thin-film transistor fabricated in single-crystalline transparent oxide semiconductor. Science 300, 1269–1272 (2003).

    Article  Google Scholar 

  5. Zhang, S. et al. Recent progress in 2D group-VA semiconductors: from theory to experiment. Chem. Soc. Rev. 47, 982–1021 (2018).

    Article  Google Scholar 

  6. Chhowalla, M., Jena, D. & Zhang, H. Two-dimensional semiconductors for transistors. Nat. Rev. Mater. 1, 16052 (2016).

    Article  Google Scholar 

  7. He, Q. et al. Quest for p-type two-dimensional semiconductors. ACS Nano 13, 12294–12300 (2019).

    Article  Google Scholar 

  8. Sanal, K. C., Vikas, L. S. & Jayaraj, M. K. Room temperature deposited transparent p-channel CuO thin film transistors. Appl. Surf. Sci. 297, 153–157 (2014).

    Article  Google Scholar 

  9. Guo, S. et al. Ultrathin tellurium dioxide: emerging direct bandgap semiconductor with high-mobility transport anisotropy. Nanoscale 10, 8397–8403 (2018).

    Article  Google Scholar 

  10. Hodgson, S. N. B. & Weng, L. Preparation of tellurite thin films from tellurium isopropoxide precursor by sol–gel processing. J. Non-Cryst. Solids 276, 195–200 (2000).

    Article  Google Scholar 

  11. Hodgson, S. N. B. & Weng, L. Chemical and sol–gel processing of tellurite glasses for optoelectronics. J. Mater. Sci. Mater. Electron. 17, 723–733 (2006).

    Article  Google Scholar 

  12. Zavabeti, A. et al. A liquid metal reaction environment for the room-temperature synthesis of atomically thin metal oxides. Science 358, 332–335 (2017).

    Article  Google Scholar 

  13. Datta, R. S. et al. Flexible two-dimensional indium tin oxide fabricated using a liquid metal printing technique. Nat. Electron. 3, 51–58 (2020).

    Article  Google Scholar 

  14. Cabrera, N. & Mott, N. F. Theory of the oxidation of metals. Rep. Prog. Phys. 12, 163–184 (1949).

    Article  Google Scholar 

  15. Greenwood, N. N. & Earnshaw, A. in Chemistry of the Elements Ch. 16, 747–788 (Elsevier Butterworth-Heinemann, 1997).

  16. Tsuchiya, Y. Phase equilibria in the liquid sulphur–tellurium system: structural changes and two-melt phase separation. J. Phys. Condens. Matter 4, 4335–4349 (1992).

    Article  Google Scholar 

  17. Ghosh, G., Sharma, R. C., Li, D. T. & Chang, Y. A. The Se–Te (selenium–tellurium) system. J. Phase Equilib. 15, 213–224 (1994).

    Article  Google Scholar 

  18. Li, D. T., Sharma, R. C. & Chang, Y. A. The S–Te (sulfur–tellurium) system. Bull. Alloy Phase Diagr. 10, 348–350 (1989).

    Article  Google Scholar 

  19. Wang, L. et al. High-performance transparent inorganic–organic hybrid thin-film n-type transistors. Nat. Mater. 5, 893–900 (2006).

    Article  Google Scholar 

  20. Nayak, P. K., Hedhili, M. N., Cha, D. & Alshareef, H. N. High performance In2O3 thin film transistors using chemically derived aluminum oxide dielectric. Appl. Phys. Lett. 103, 033518 (2013).

    Article  Google Scholar 

  21. Chamlagain, B. et al. Mobility improvement and temperature dependence in MoSe2 field-effect transistors on parylene-C substrate. ACS Nano 8, 5079–5088 (2014).

    Article  Google Scholar 

  22. Wurdack, M. et al. Ultrathin Ga2O3 glass: a large-scale passivation and protection material for monolayer WS2. Adv. Mater. 33, 2005732 (2020).

    Article  Google Scholar 

  23. Lee, G.-H. et al. Highly stable, dual-gated MoS2 transistors encapsulated by hexagonal boron nitride with gate-controllable contact, resistance and threshold voltage. ACS Nano 9, 7019–7026 (2015).

    Article  Google Scholar 

  24. Geim, A. K. & Grigorieva, I. V. Van der Waals heterostructures. Nature 499, 419–425 (2013).

    Article  Google Scholar 

  25. Gu, J., Chakraborty, B., Khatoniar, M. & Menon, V. M. A room-temperature polariton light-emitting diode based on monolayer WS2. Nat. Nanotechnol. 14, 1024–1028 (2019).

    Article  Google Scholar 

  26. Laun, J., Vilela Oliveira, D. & Bredow, T. Consistent Gaussian basis sets of double- and triple-zeta valence with polarization quality of the fifth period for solid-state calculations. J. Comput. Chem. 39, 1285–1290 (2018).

    Article  Google Scholar 

  27. CRYSTAL—Basis Sets Library (CRYSTAL Theoretical Chemistry Group, Univ. Torino);

  28. Grimme, S. Semiempirical GGA-type density functional constructed with a long-range dispersion correction. J. Comput. Chem. 27, 1787–1799 (2006).

    Article  Google Scholar 

  29. Monkhorst, H. J. & Pack, J. D. Special points for Brillouin-zone integrations. Phys. Rev. B 13, 5188–5192 (1976).

    Article  MathSciNet  Google Scholar 

  30. Dovesi, R. et al. CRYSTAL14: a program for the ab initio investigation of crystalline solids. Int. J. Quantum Chem. 114, 1287–1317 (2014).

    Article  Google Scholar 

  31. Dovesi, R. et al. CRYSTAL14 User’s Manual (Univ. Torino, 2014).

  32. Crystallography Open Database COD ID 9008125;

  33. Qiao, J., Kong, X., Hu, Z.-X., Yang, F. & Ji, W. High-mobility transport anisotropy and linear dichroism in few-layer black phosphorus. Nat. Commun. 5, 4475 (2014).

    Article  Google Scholar 

  34. Momma, K. & Izumi, F. VESTA 3 for three-dimensional visualization of crystal, volumetric and morphology data. J. Appl. Crystallogr. 44, 1272–1276 (2011).

    Article  Google Scholar 

  35. Olin, Å., Nolang, B., Osadchii, E. G., Öhman, L.-O. & Rsen, E. Chemical Thermodynamics of Selenium. Vol. 7, 41 (Elsevier, 2005).

  36. Ceriotti, M., Pietrucci, F. & Bernasconi, M. Ab initio study of the vibrational properties of crystalline TeO2: the α, β and γ phases. Phys. Rev. B 73, 104304 (2006).

    Article  Google Scholar 

  37. Beyer, H. Verfeinerung der Kristallstruktur von Tellurit, dem rhombischen TeO2. Z. Kristallogr. Cryst. Mater. 124, 228–237 (1967).

    Article  Google Scholar 

  38. Mirgorodsky, A. P., Merle-Méjean, T., Champarnaud, J. C., Thomas, P. & Frit, B. Dynamics and structure of TeO2 polymorphs: model treatment of paratellurite and tellurite; Raman scattering evidence for new γ- and δ-phases. J. Phys. Chem. Solids 61, 501–509 (2000).

    Article  Google Scholar 

  39. Zhang, W. L., Zhang, S., Yang, M. & Chen, T. P. Microstructure of magnetron sputtered amorphous SiOx films: formation of amorphous Si core−shell nanoclusters. J. Phys. Chem. C 114, 2414–2420 (2010).

    Article  Google Scholar 

  40. Di Nardo, S., Lozzi, L., Passacantando, M., Picozzi, P. & Santucci, S. Reactivity towards oxygen of TeSi(100) surfaces investigated by ultraviolet photoelectron spectroscopy, X-ray photoelectron spectroscopy and low energy electron diffraction spectroscopy. J. Electron Spectrosc. 74, 129–134 (1995).

    Article  Google Scholar 

  41. Shimada, K. et al. Photoemission study of itinerant ferromagnet Cr1 − dTe. Phys. Rev. B 53, 7673–7683 (1996).

    Article  Google Scholar 

  42. Charton, P., Gengembre, L. & Armand, P. TeO2–WO3 glasses: infrared, XPS and XANES structural characterizations. J. Solid State Chem. 168, 175–183 (2002).

    Article  Google Scholar 

  43. Shalvoy, R. B., Fisher, G. B. & Stiles, P. J. Bond ionicity and structural stability of some average-valence-five materials studied by X-ray photoemission. Phys. Rev. B 15, 1680–1697 (1977).

    Article  Google Scholar 

Download references


T.D. acknowledges funds received from the Australian Research Council (ARC) through the DECRA scheme (DE190100100). A.Z. thanks the University of Melbourne for the support received through the McKenzie postdoctoral fellowship programme. This work was supported by ARC Centre of Excellence FLEET (CE170100039) and Exciton Science (CE170100026). We thank RMIT University’s Microscopy and Microanalysis Facility (RMMF), a linked laboratory of the Australian Microscopy and Microanalysis Research Facility (AMMRF), and RMIT University’s MicroNano Research Facility (MNRF) for scientific and technical support. The Cypher ES AFM instrument was funded in part by grant no. LE170100096 from the ARC. This project was also supported by computational resources provided by the Australian government through the National Computational Infrastructure National Facility (NCI-NF) and the Pawsey Supercomputer Centre (ARC). A.E. is supported by the Jack Brockhoff Foundation (JBF grant no. 4655-2019-AE). D.L.C. is supported by the ARC under Discovery Project grant no. DP190102852.

Author information

Authors and Affiliations



The project was designed and directed by T.D., C.F.M. and A.Z. A.Z. and P.A. synthesized the chalcogen mixture and developed the synthesis procedure for 2D β-TeO2 while also conducting XPS and Raman measurements. A.Z., P.A. and B.Y.Z. performed the AFM imaging. A.E. performed atomic-resolution HR-AFM imaging. A.Z. performed TEM/SAED and HRTEM imaging. P.A. led the device fabrication with contributions from H.T., N.S., A.J., K.A.M. and J.v.E. J.G.P., A.Z. and P.A. characterized the FET devices. B.J.M. carried out UPS measurements and assisted with the XPS analysis. M.W. performed 2D nanosheet transfer experiments. D.L.C. conducted and interpreted Hall effect measurements. S.P.R. performed DFT calculations. T.D., C.F.M., K.K.-Z., A.Z. and P.A. analysed the material and device characteristics and drafted the manuscript. All authors revised the manuscript.

Corresponding authors

Correspondence to Ali Zavabeti, Chris F. McConville or Torben Daeneke.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Peer review information Nature Electronics thanks Seungwu Han, Chun-Hu Cheng and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

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

Extended data

Extended Data Fig. 1 Roll-synthesis technique characterization.

a, Maximum droplet velocity achieved when droplet size was varied (Supplementary Videos 1 and 2). Lower speeds can be applied to the larger droplets as rolling too fast causes the fragmentation. b, Oxide thickness against time shows no significant change of the sheet thickness when prolonging the oxidation time. c, Rolling time-steps against substrate coverage and sheets lateral dimensions (Supplementary Video 3). Time-steps are defined as resting molten droplet before rolling a droplet-diameter length. Each error bar represents ± 1 standard deviation from four measurements. Discussion on printing parameters can be found in Supplementary Note 1.

Extended Data Fig. 2 Energy-dispersive X-ray spectroscopy (EDXS) elemental composition spectrum.

The composition of the chalcogen mixture was determined to be 95 wt% selenium and 5 wt% tellurium.

Extended Data Fig. 3 XPS spectra taken from the transferred TeO2 nanosheets and XPS elemental map.

The results reveal the composition of the 2D sheets, shown in Fig. 1a (97.7 mol% TeO2 and 2.3 mol% Se). a, The peak in the O 1 s binding energy region located at 530.6 eV is associated with TeO242 b, The Te4+ 3d5/2 peak is located at 576.4 eV42. c, A small amount of Se was detected in the Se 3d region with a peak located for the 3d5/2 at 55.2 eV43. d, XPS elemental map of a deposited flake on the right indicates the TeO2 flake, while Se is revealed as a sparse residue on the substrate.

Extended Data Fig. 4 Optical images of TeO2.

a-i, Transferred 2D TeO2 sheets on a variety of substrates. The labels I-IX refer to the different substrates, while X represents the 2D TeO2 sheet. j, A thicker TeO2 sheet can be obtained from repeated roll transfer across the same area. The optical image and AFM step height profile reveal multiple TeO2 sheets stacked on top of one another, which caused an increase in thickness. k-m, Transfer of a TeO2 flake from a GaAs substrate onto a SiO2 substrate. Optical images of the TeO2 flake on GaAs, polypropylene-carbonate (PPC) and SiO2 substrate, respectively, demonstrate the successful transfer process (See Methods section for the transfer protocol). Black scale bars are 50 μm.

Extended Data Fig. 5 High-resolution AFM.

a, HRAFM image of 2D β-TeO2 on a Si/SiO2 wafer b, The observed spacing is shown in the model crystal structure.

Extended Data Fig. 6 Hole effective mass.

The calculated hole effective mass (\(m_h^ \ast\)) of 0.51 obtained from Equation S2 utilizing data from STS measurement (see Supplementary Note 2).

Extended Data Fig. 7 2D β-TeO2 valence band spectrum obtained from UPS.

The work function of the material was located at 3.88 eV.

Extended Data Fig. 8 Atomic Orbital Projected DOS plot of the bilayer.

The results show which types of atomic orbitals of Te and O contribute to the upper valence bands. The projections are partitioned into the different atomic orbital types (s, p, d) for O and Te. The plot clearly shows that in the region near the valence band maximum, O and Te p orbitals form the major contribution to the bands, suggesting π-bonding.

Extended Data Fig. 9 Conductive path in bilayer β-TeO2.

For simplicity, the crystal structure of the bottom layer of the two layers found in unit cell thick β-TeO2 (Fig. 1c) is shown. The charge density shown in Fig. 1c suggests that conduction most efficiently occurs close to the interlayer band edge (top side of the displayed monolayer), while the DOS associated with the VBM is sparse at the bottom of the shown β-TeO2 layer. Here the conduction pathways are shown along the b-axis (green) and the a-axis (red). The DFT calculations indicate a hole mobility of 7690 cm2 V-1 s-1 along the b-axis and 436 cm2 V-1 s-1 along the a-axis, respectively. The higher mobility along the b-axis arises due to the shorter mean free path lengths and transport through regions of high DOS, while transport along the a-axis requires a longer mean free path that diverts into regions of low DOS.

Extended Data Fig. 10 Stability testing of a TeO2 field-effect transistor showing 1500 On-Off cycles.

No degradation in performance is observed. Five On-Off cycles are shown on the right.

Supplementary information

Supplementary Information

Supplementary notes 1–5, Figs. 1–6 and Tables 1–3.

Supplementary Video 1

Roll-transfer of a droplet with a diameter less than 2 mm.

Supplementary Video 2

Roll-transfer of a droplet with a diameter larger than 2 mm.

Supplementary Video 3

Roll-transfer of a droplet moving every 3 min, and the corresponding substrate coverage.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Zavabeti, A., Aukarasereenont, P., Tuohey, H. et al. High-mobility p-type semiconducting two-dimensional β-TeO2. Nat Electron 4, 277–283 (2021).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing