JoVE Journal > Engineering
Summary
Abstract
Introduction
Protocol
Results
Discussion
Disclosures
Acknowledgements
Materials
References
한국어

Automatically Generated
Please note that all translations are automatically generated. Click here for the English version.
Engineering

Electric-field Control of Electronic States in WS2 Nanodevices by Electrolyte Gating

Published: April 12, 2018
doi:
10.3791/56862
, , , , , , ,
1Quantum-Phase Electronics Center (QPEC) and Department of Applied Physics,The University of Tokyo, 2Materials Sciences Division,Lawrence Berkeley National Laboratory, 3Institute of Scientific and Industrial Research,Osaka University, 4Max Planck Institute for Solid State Research, 5RIKEN Center for Emergent Matter Science (CEMS)

Summary

Here, we present a protocol to control the carrier number in solids by using the electrolyte.

Abstract

A method of carrier number control by electrolyte gating is demonstrated. We have obtained WS2 thin flakes with atomically flat surface via scotch tape method or individual WS2 nanotubes by dispersing the suspension of WS2 nanotubes. The selected samples have been fabricated into devices by the use of the electron beam lithography and electrolyte is put on the devices. We have characterized the electronic properties of the devices under applying the gate voltage. In the small gate voltage region, ions in the electrolyte are accumulated on the surface of the samples which leads to the large electric potential drop and resultant electrostatic carrier doping at the interface. Ambipolar transfer curve has been observed in this electrostatic doping region. When the gate voltage is further increased, we met another drastic increase of source-drain current which implies that ions are intercalated into layers of WS2 and electrochemical carrier doping is realized. In such electrochemical doping region, superconductivity has been observed. The focused technique provides a powerful strategy for achieving the electric-filed-induced quantum phase transition.

Introduction

Control of the carrier number is the key technique for realizing the quantum phase transition in solids1. In the conventional field effect transistor (FET), it is achieved by use of the solid gate1,2. In such a device, electric potential gradient is uniform throughout the dielectric materials so that induced carrier number at the interface is limited, shown in Figure 1a.

On the other hand, we can achieve the higher carrier density at the interface or bulk by replacing the solid dielectric materials with ionic gels/liquids or polymer electrolytes3,4,5,6,7,8,9,10,11 (Figure 1b). In the electrostatic doping by use of the ionic liquid, electric double layer transistor (EDLT) structure is formed at the interface between ionic liquid and sample, generating strong electric field (>0.5 V/Å) even at low bias voltage. Resultant high carrier density (>1014 cm-2) induced at the interface10,12,13 cause the novel electronic properties or quantum phase transition such as electric-field-induced ferromagnetism14, Coulomb blockade15, ambipolar transport16,17,18,19,20,21,22,23,24,25,26,27, formation of p-n junction and resultant electroluminance28,29,30, large modulation of thermoelectric powers31,32, charge density wave and Mott transitions33,34,35, and electric-field-induced insulator-metal transition36,37 including electric-field-induced superconductivity9,10,11,38,39,40,41,42,43,44,45,46,47,48,49.

In the electrolyte gating (Figure 1c), ions are not only accumulated at the interface to form EDLT, but can be also intercalated into layers of two-dimensional materials via thermal diffusion without damaging sample under applying the large gate voltage, leading to the electrochemical doping8,9,11,34,38,50,51,52,53. Thus, we can drastically change the carrier number compared to the conventional field effect transistor using the solid gate. In particular, the electric-field-induced superconductivity9,11,34,38,50 is realized by use of electrolyte gating in region of large carrier number where we cannot access by the conventional solid gating method.

In this article, we introduce this unique technique of carrier number control in solids and overview the transistor operation and electric-field-induced superconductivity in semiconducting WS2 samples such as WS2 flakes and WS2 nanotubes54,55,56,57.

Protocol

1. Dispersion of WS 2 Nanotubes (NTs) on substrate Disperse WS2 NT powders into isopropyl alcohol (IPA, concentration more than 99.8%) with proper diluted ratio (about 0.1 mg/mL) by sonication for 20 min. NOTE: The long-time sonication helps to make WS2 NTs uniformly suspended in IPA liquid and to separate well-formed individual WS2 NTs from amorphous WS2 or other junks, as well as to remove the garbage accumulating on WS2 NTs surface. <…

Representative Results

The typical transistor operations of an individual WS2 NT and a WS2 flake devices are shown in Figure 3a and 3b, respectively, where the source drain current (IDS) as a function of the gate voltage (VG) nicely operates in an ambipolar mode, showing a remarkable contrast to the unipolar gate response by the conventional solid gated FET in previous publication58</su…

Discussion

In both WS2 NTs and flakes, we have successfully controlled the electric properties by electrostatic or electro chemical carrier doping.

In electrostatic doping region, ambipolar transistor operation has been observed. Such ambipolar transfer curve with a high on/off ratio (>102) observed in low bias voltage indicates the effective carrier doping at the interface of electrolyte gating technique for tuning the Fermi level of these systems.

A…

Disclosures

The authors have nothing to disclose.

Acknowledgements

We acknowledge the following financial support; Grant-in-Aid for Specially Promoted Research (No. 25000003) from JSPS, Grant-in-Aid for Research Activity Start-up (No.15H06133) and Challenging Research (Exploratory) (No. JP17K18748) from MEXT of Japan.

Materials

Sonication machine SND Co., Ltd. US-2 http://www.senjyou.jp/
Spin-coater machine ACTIVE Co.,Ltd. ACT-300AII http://www.acti-ve.co.jp/spincoater/standard/act300a2.html
Hot-plate TAIYO HP131224 http://www.taiyo-kabu.co.jp/products/detail.php?product_id=431
Optical Microscopy OLYMPUS BX51 https://www.olympus-ims.com/ja/microscope/bx51p/
Electron Beam Lithography machine ELIONIX INC. ELS-7500I https://www.elionix.co.jp/index.html
Scribing machine TOKYO SEIMITSU CO., LTD. A-WS-100A http://www.accretech.jp/english/product/semicon/wms/aws100s.html
Wire-bonding machine WEST·BOND  7476D-79 https://www.hisol.jp/products/bonder/wire/mgb/b.html
Physical Properties Measurement System Quantum Design PPMS http://www.qdusa.com/products/ppms.html
Lock-in amplifier Stanford Research Systems SRS830 http://www.thinksrs.com/products/SR810830.htm
Source meter Textronix KEITHLEY 2612A http://www.tek.com/keithley-source-measure-units/smu-2600b-series-sourcemeter
KClO4 Sigma-Aldrich 241830 http://www.sigmaaldrich.com/catalog/product/sigald/241830?lang=ja&region=JP
PEG WAKO 168-09075 http://www.siyaku.com/uh/Shs.do?dspCode=W01W0116-0907
IPA WAKO 169-28121 http://www.siyaku.com/uh/Shs.do?dspWkfcode=169-28121
MIBK WAKO 131-05645 http://www.siyaku.com/uh/Shs.do?dspCode=W01W0113-0564
PMMA MicroChem PMMA http://microchem.com/Prod-PMMA.htm
Acetone WAKO 012-26821 http://www.siyaku.com/uh/Shs.do?dspWkfcode=012-26821
DOWNLOAD MATERIALS LIST

References

  1. Ahn, C. H., et al. Electrostatic modification of novel materials. Rev. Mod. Phys. 78, 1185-1212 (2006).
  2. Ahn, C. H., Triscone, J. M., Mannhart, J. Electric field effect in correlated oxide systems. Nature. 424, 1015-1018 (2003).
  3. Panzer, M. J., Frisbie, C. D. Polymer Electrolyte Gate Dielectric Reveals Finite Windows of High Conductivity in Organic Thin Film Transistors at High Charge Carrier Densities. J. Am. Chem. Soc. 127, 6960-6961 (2005).
  4. Panzer, M. J., Frisbie, C. D. High charge carrier densities and conductance maxima in single-crystal organic field-effect transistors with a polymer electrolyte gate dielectric. Appl. Phys. Lett. 88, 203504 (2006).
  5. Misra, R., McCarthy, M., Hebard, A. F. Electric field gating with ionic liquids. Appl. Phys. Lett. 90, 052905 (2007).
  6. Ono, S., Seki, S., Hirahara, R., Tominari, Y., Takeya, J. High-mobility, low-power, and fast-switching organic field-effect transistors with ionic liquids. Appl. Phys. Lett. 92, 103313 (2008).
  7. Lee, J., Panzer, M. J., He, Y., Lodge, T. P., Frisbie, C. D. Ion Gel Gated Polymer Thin-Film Transistors. J. Am. Chem. Soc. 129, 4532-4533 (2007).
  8. Fujimoto, T., Awaga, K. Electric-double-layer field-effect transistors with ionic liquids. Phys. Chem. Chem. Phys. 15, 8983-9006 (2013).
  9. Du, H., Lin, X., Xu, Z., Chu, D. Electric double-layer transistors: a review of recent progress. J. Mater. Sci. 50, 5641-5673 (2015).
  10. Ueno, K., et al. Field-induced superconductivity in electric double layer transistors. J. Phys. Soc. Jpn. 83, 032001 (2014).
  11. Bisri, S. Z., Shimizu, S., Nakano, M., Iwasa, Y. Endeavor of Iontronics: From Fundamentals to Applications of Ion-Controlled Electronics. Adv. Mater. 29, 1607054 (2017).
  12. Yuan, H. T., et al. High-density carrier accumulation in ZnO field-effect transistors gated by electric double layers of ionic liquids. Adv. Funct. Mater. 19, 1046-1053 (2009).
  13. Yuan, H., et al. Zeeman-type spin splitting controlled by an electric field. Nat Phys. 9, 563-569 (2013).
  14. Yamada, Y., et al. Electrically induced ferromagnetism at room temperature in cobalt-doped titanium dioxide. Science. 332, 1065-1067 (2011).
  15. Shibata, K., et al. Large modulation of zero-dimensional electronic states in quantum dots by electric-double-layer gating. Nat Commun. 4, 2664 (2013).
  16. Krüger, M., Buitelaar, M. R., Nussbaumer, T., Schönenbergera, C. Electrochemical carbon nanotube field-effect transistor. Appl. Phys. Lett. 78, 1291 (2001).
  17. Rosenblatt, S., Yaish, Y., Park, J., Gore, J., Sazonova, V., McEuen, P. L. High Performance Electrolyte Gated Carbon Nanotube Transistors. Nano Lett. 2, 869-872 (2002).
  18. Yuan, H. T., et al. Liquid-gated ambipolar transport in ultrathin films of a topological insulator Bi2Te3. Nano Lett. 11, 2601-2605 (2011).
  19. Zhang, Y., Ye, J., Matsuhashi, Y., Iwasa, Y. Ambipolar MoS2 thin flake transistor. Nano Lett. 12, 1136-1140 (2012).
  20. Braga, D., et al. Quantitative determination of the band gap of WS2 with ambipolar ionic liquid-gated transistors. Nano lett. 12, 5218-5223 (2012).
  21. Saito, Y., Iwasa, Y. Ambipolar insulator-to-metal transition in black phosphorus by ionic-liquid gating. ACS Nano. 9, 3192-3198 (2015).
  22. Sugahara, M., et al. Ambipolar transistors based on random networks of WS2 nanotubes. Appl. Phys. Express. 9, 075001 (2016).
  23. Kang, M. S., Lee, J., Norris, D. J., Frisbie, C. D. High Carrier Densities Achieved at Low Voltages in Ambipolar PbSe Nanocrystal Thin-Film Transistors. Nano Lett. 9, 3848-3852 (2009).
  24. Bisri, S. Z., et al. Low Driving Voltage and High Mobility Ambipolar Field-Effect Transistors with PbS Colloidal Nanocrystals. Adv. Mater. 25, 4309-4314 (2013).
  25. Dasgupta, S., et al. Printed and Electrochemically Gated, High-Mobility, Inorganic Oxide Nanoparticle FETs and Their Suitability for High-Frequency Applications. Adv. Funct. Mater. 22, 4909-4919 (2012).
  26. Thiemann, S., Gruber, M., Lokteva, I., Hirschmann, J., Halik, M., Zaumseil, J. High-Mobility ZnO Nanorod Field-Effect Transistors by Self-Alignment and Electrolyte-Gating. Acs Appl Mater Inter. 5, 1656-1662 (2013).
  27. Wong, A. T., et al. Impact of gate geometry on ionic liquid gated ionotronic systems. APL Mater. 5, 042501 (2017).
  28. Zhang, Y. J., Oka, T., Suzuki, R., Ye, J. T., Iwasa, Y. Electrically switchable chiral light-emitting transistor. Science. 344, 725-728 (2014).
  29. Zhang, Y. J., Yoshida, M., Suzuki, R., Iwasa, Y. 2D crystals of transition metal dichalcogenide and their iontronic functionalities. 2D Materials. 2, 044004 (2015).
  30. Onga, M., Zhang, Y. J., Suzuki, R., Iwasa, Y. High circular polarization in electroluminescence from MoSe2. Appl Phys Lett. 108, 073107 (2016).
  31. Yoshida, M., et al. Gate-optimized thermoelectric power factor in ultrathin WSe2 single crystals. Nano Lett. 16, 2061-2065 (2016).
  32. Saito, Y., et al. Gate-tuned thermoelectric power in black phosphorus. Nano Lett. 16, 4819-4824 (2016).
  33. Yoshida, M., et al. Controlling charge-density-wave states in nano-thick crystals of 1T-TaS2. Sci. Rep. 4, 7302 (2014).
  34. Yu, Y., et al. Gate-tunable phase transitions in thin flakes of 1T-TaS2. Nat Nanotechnol. 10, 270-276 (2015).
  35. Nakano, M., et al. Collective bulk carrier delocalization driven by electrostatic surface charge accumulation. Nature. 487, 459-462 (2012).
  36. Shimotani, H., Asanuma, H., Iwasa, Y. Electric Double Layer Transistor of Organic Semiconductor Crystals in a Four-Probe Configuration. Jpn. J. Appl. Phys. 46, 3613 (2007).
  37. Shi, W., et al. Transport Properties of Polymer Semiconductor Controlled by Ionic Liquid as a Gate Dielectric and a Pressure Medium. Adv. Funct. Mater. 24, 2005-2012 (2014).
  38. Shi, W., et al. Superconductivity series in transition metal dichalcogenides by ionic gating. Sci. Rep. 5, 12534 (2015).
  39. Saito, Y., Nojima, T., Iwasa, Y. Gate-induced superconductivity in two-dimensional atomic crystals. Supercond. Sci. Technol. 29, 093001 (2016).
  40. Saito, Y., Nojima, T., Iwasa, Y. Highly crystalline 2D superconductors. Nature Rev. Mater. 2, 16094 (2016).
  41. Ueno, K., et al. Electric-field-induced superconductivity in an insulator. Nat Mater. 7, 855-858 (2008).
  42. Ye, J. T., et al. Liquid-gated interface superconductivity on an atomically flat film. Nat Mater. 9, 125-128 (2010).
  43. Ueno, K., et al. Discovery of superconductivity in KTaO3 by electrostatic carrier doping. Nat Nanotechnol. 6, 408-412 (2011).
  44. Ye, J. T., et al. Superconducting dome in a gate-tuned band insulator. Science. 338, 1193-1196 (2012).
  45. Saito, Y., Kasahara, Y., Ye, J., Iwasa, Y., Nojima, T. Metallic ground state in an ion-gated two-dimensional superconductor. Science. 350, 409-413 (2015).
  46. Saito, Y., et al. Superconductivity protected by spin-valley locking in ion-gated MoS2. Nat Phys. 12, 144-149 (2016).
  47. Costanzo, D., et al. Gate-induced superconductivity in atomically thin MoS2 crystals. Nat Nanotechnol. 11, 339-344 (2016).
  48. Jo, S., Costanzo, D., Berger, H., Morpurgo, A. F. Electrostatically induced superconductivity at the surface of WS2. Nano Lett. 15, 1197-1202 (2015).
  49. Lei, B., et al. Gate-tuned superconductor-insulator transition in (Li,Fe)OHFeSe. Phys. Rev. B. 93, 060501 (2016).
  50. Qin, F., et al. Superconductivity in a chiral nanotube. Nat Commun. 8, 14465 (2017).
  51. Zhao, J., et al. Lithium-ion-based solid electrolyte tuning of the carrier density in graphene. Sci. Rep. 6, 34816 (2016).
  52. Lei, B., et al. Tuning phase transitions in FeSe thin flakes by field-effect transistor with solid ion conductor as the gate dielectric. Phys. Rev. B. 95, 020503 (2017).
  53. Zhu, C. S., et al. Tuning electronic properties of FeSe0.5Te0.5 thin flakes using a solid ion conductor field-effect transistor. Phys. Rev. B. 95, 174513 (2017).
  54. Tenne, R., Margulis, L., Genut, M., Hodes, G. Polyhedral and cylindrical structures of tungsten disulphide. Nature. 360, 444-446 (1992).
  55. Rothschild, A., Sloan, J., Tenne, R. Growth of WS2 nanotubes phases. J. Am. Chem. Soc. 122, 5169-5179 (2000).
  56. Zak, A., et al. Scaling-up of the WS2 nanotubes synthesis. Fullerenes, Nanotubes and Carbon Nanostruct. 19, 18-26 (2010).
  57. Rao, C. N. R., Nath, M. Inorganic nanotubes. Dalton T. 1, 1-24 (2003).
  58. Levi, R., Bitton, O., Leitus, G., Tenne, R., Joselevich, E. Field-effect transistors based on WS2 nanotubes with high current-carrying capacity. Nano Lett. 13, 3736-3741 (2013).
  59. Shiogai, J., et al. Electric-field-induced superconductivity in electrochemically etched ultrathin FeSe films on SrTiO3 and MgO. Nat Phys. 12, 42-46 (2016).
  60. Shiogai, J., et al. Unified trend of superconducting transition temperature versus Hall coefficient for ultrathin FeSe films prepared on different oxide substrates. Phys. Rev. B. 95, 115101 (2017).
  61. Jeong, J., et al. Suppression of Metal-Insulator Transition in VO2 by Electric Field-Induced Oxygen Vacancy Formation. Science. 339, 1402-1405 (2013).
  62. Schladt, T. D., et al. Crystal-Facet-Dependent Metallization in Electrolyte-Gated Rutile TiO2 Single Crystals. ACS Nano. 7, 8074-8081 (2013).
  63. Lu, N., et al. Electric-field control of tri-state phase transformation with a selective dual-ion switch. Nature. 546, 124-128 (2017).
  64. Suda, M., Kato, R., Yamamoto, H. M. Light-induced superconductivity using a photoactive electric double layer. Science. 347, 743-746 (2015).

Tags

Electric-field ControlElectronic StatesWS2 NanodevicesElectrolyte GatingQuantum Phase TransitionsElectric-field-induced SuperconductivityTungsten Disulfide NanotubesTungsten Disulfide FlakesPMMA CoatingSpin-coating

Play Video
PDF
DOI
DOWNLOAD MATERIALS LIST
Cite This Article
Qin, F., Ideue, T., Shi, W., Zhang, Y., Suzuki, R., Yoshida, M., Saito, Y., Iwasa, Y. Electric-field Control of Electronic States in WS2 Nanodevices by Electrolyte Gating. J. Vis. Exp. (134), e56862, doi:10.3791/56862 (2018).
Download Citation
Reprints and Permissions

View Video

✖

To prove you're not a robot, please enter the text in the image below

CAPTCHA Image
Play CAPTCHA Audio
Refresh Image