Temperature- and thickness-dependence of robust out-of-plane ferroelectricity in CVD grown ultrathin van der Waals α-In2Se3 layers

  • 35 Accesses


Two-dimensional (2D) ferroelectric materials with unique structure and extraordinary optoelectrical properties have attracted intensive research in the field of nanoelectronic and optoelectronic devices, such as optical sensors, transistors, photovoltaics and non-volatile memory devices. However, the transition temperature of the reported ferroelectrics in 2D limit is generally low or slightly above room temperature, hampering their applications in high-temperature electronic devices. Here, we report the robust high-temperature ferroelectricity in 2D α-In2Se3, grown by chemical vapor deposition (CVD), exhibiting an out-of-plane spontaneous polarization reaching above 200 °C. The polarization switching and ferroelectric domains are observed in In2Se3 nanoflakes in a wide temperature range. The coercive field of the CVD grown ferroelectric layers illustrates a room-temperature thickness dependency and increases drastically when the film thickness decreases; whereas there is no large variance in the coercive field at different temperature from the samples with identical thickness. The results show the stable ferroelectricity of In2Se3 nanoflakes maintained at high temperature and open up the opportunities of 2D materials for novel applications in high-temperature nanoelectronic devices.

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

Access options

Buy single article

Instant unlimited access to the full article PDF.

US$ 39.95

Price includes VAT for USA


  1. [1]

    Cui C. J.; Xue, F.; Hu W. J.; Li L. J. Two-dimensional materials with piezoelectric and ferroelectric functionalities. NPJ 2D Mater. Appl. 2018, 2, 18.

  2. [2]

    Zhang, Y.; Jie W. J.; Chen, P.; Liu W. W.; Hao J. H. Ferroelectric and piezoelectric effects on the optical process in advanced materials and devices. Adv. Mater. 2018, 30, 1707007.

  3. [3]

    Jeong D. S.; Thomas, R.; Katiyar R. S.; Scott J. F.; Kohlstedt, H.; Petraru, A.; Hwang C. S. Emerging memories: resistive switching mechanisms and current status. Rep. Prog. Phys. 2012, 75, 076502.

  4. [4]

    Zheng F. G.; Xin, Y.; Huang, W.; Zhang J. X.; Wang X. F.; Shen M. R.; Dong, W.; Fang, L.; Bai Y. B.; Shen X. Q.; Hao J. H. Above 1% efficiency of a ferroelectric solar cell based on the Pb(Zr, Ti)O3 film. J. Mater. Chem. A2014, 2, 1363–1368.

  5. [5]

    Yang Z. B.; Hao J. H. Recent progress in 2D layered III-VI semiconductors and their heterostructures for optoelectronic device applications. Adv. Mater. Technol. 2019, 4, 1900108.

  6. [6]

    Yuan S. G.; Yang Z. B.; Xie, C.; Yan, F.; Dai J. Y.; Lau S. P.; Chan H. L. W.; Hao J. H. Ferroelectric-driven performance enhancement of graphene field-effect transistors based on vertical tunneling heterostructures. Adv. Mater. 2016, 28, 10048–10054.

  7. [7]

    Gao, P.; Zhang Z. Y.; Li M. Q.; Ishikawa, R.; Feng, B.; Liu H. J.; Huang Y. L.; Shibata, N.; Ma X. M.; Chen S. L. et al. Possible absence of critical thickness and size effect in ultrathin perovskite ferroelectric films. Nat. Commun. 2017, 8, 15549.

  8. [8]

    Junquera, J.; Ghosez, P. Critical thickness for ferroelectricity in perovskite ultrathin films. Nature, 2003, 422, 506.

  9. [9]

    Lee, D.; Lu, H.; Gu, Y.; Choi S. Y.; Li S. D.; Ryu, S.; Paudel T. R.; Song, K.; Mikheev, E.; Lee, S. et al. Emergence of room-temperature ferroelectricity at reduced dimensions. Science2015, 349, 1314–1317.

  10. [10]

    Lang X. Y. and Jiang, Q. Size and interface effects on Curie temperature of perovskite ferroelectric nanosolids. J. Nanoparticle Res. 2007, 9, 595–603.

  11. [11]

    Balachandran P. V.; Xue D. Z.; Lookman, T. Structure-curie temperature relationships in BaTiO3-based ferroelectric perovskites: Anomalous behavior of (Ba, Cd) TiO3 from DFT, statistical inference, and experiments. Phys. Rev. B. 2016, 93, 144111.

  12. [12]

    Chang, K.; Liu J. W.; Lin H. C.; Wang, N.; Zhao, K.; Zhang A. M.; Jin, F.; Zhong, Y.; Hu X. P.; Duan W. H. et al. Discovery of robust in-plane ferroelectricity in atomic-thick SnTe. Science2016, 353, 274–278.

  13. [13]

    Fei, R. X; Kang, W.; Yang, L. Ferroelectricity and phase transitions in monolayer group-IV monochalcogenides. Phys. Rev. Lett. 2016, 117, 097601.

  14. [14]

    Liu, F. C.; You, L.; Seyler K. L.; Li, X. B; Yu, P.; Lin, J. H; Wang, X. W; Zhou, J. D; Wang, H.; He H. Y. et al. Room-temperature ferroelectricity in CuInP2S6 ultrathin flakes. Nat. Commun. 2016, 7, 12357.

  15. [15]

    Yuan S. G.; Luo, X.; Chan H. L.; Xiao C. C.; Dai Y. W.; Xie M. H.; Hao J. H. Room-temperature ferroelectricity in MoTe2 down to the atomic monolayer limit. Nat. Commun. 2019, 10, 1775.

  16. [16]

    Fei Z. Y.; Zhao W. J.; Palomaki T. A.; Sun, B.; Miller M. K.; Zhao Z. Y.; Yan J. Q.; Xu X. D.; Cobden D. H. Ferroelectric switching of a two-dimensional metal. Nature, 2018, 560, 336.

  17. [17]

    Ding W. J.; Zhu J. B.; Wang, Z.; Gao Y. F.; Xiao, D.; Gu, Y.; Zhang Z. Y.; Zhu W. G. Prediction of intrinsic two-dimensional ferroelectrics in In2Se3 and other III2-VI3 van der Waals materials. Nat. Commun. 2016, 8, 14956.

  18. [18]

    Zhou, Y.; Wu, D.; Zhu Y. H.; Cho, Y.; He, Q.; Yang, X.; Herrera, K.; Chu Z. D.; Han, Y.; Downer M. C. et al. Out-of-plane piezoelectricity and ferroelectricity in layered α-In2Se3 nanoflakes. Nano Lett. 2017, 17, 5508–5513.

  19. [19]

    Cui C. J.; Hu W. J.; Yan X. X.; Addiego, C.; Gao W. P.; Wang, Y.; Wang, Z.; Li L. Z.; Cheng Y. C.; Li, P. et al. Intercorrelated in-plane and out-of-plane ferroelectricity in ultrathin two-dimensional layered semiconductor In2Se3. Nano Lett. 2018, 18, 1253–1258.

  20. [20]

    Poh S. M.; Tan S. J. R.; Wang, H.; Song, P.; Abidi I. H.; Zhao X. X.; Dan J. D.; Chen J. S.; Luo Z. T.; Pennycook S. J. et al. Molecular-beam epitaxy of two-dimensional In2Se3 and its giant electroresistance switching in ferroresistive memory junction. Nano Lett. 2018, 18, 6340–6346.

  21. [21]

    Xue, F.; Hu W. J.; Lee K. C.; Lu L. S.; Zhang J. W.; Tang H. L.; Han, A.; Hsu W. T.; Tu S. B.; Chang W. H. et al. Room-temperature ferroelectricity in hexagonally layered α-In2Se3 nanoflakes down to the monolayer limit. Adv. Funct. Mater. 2018, 28, 1803738.

  22. [22]

    Xiao, J.; Zhu H. Y.; Wang, Y.; Feng, W.; Hu Y. X.; Dasgupta, A.; Han Y. M.; Wang, Y.; Muller D. A.; Martin L. W. et al. Intrinsic two-dimensional ferroelectricity with dipole locking. Phys. Rev. Lett. 2018, 120, 227601.

  23. [23]

    Wan S. Y.; Li, Y.; Li, W.; Mao X. Y.; Zhu W. G.; Zeng H. L. Room-temperature ferroelectricity and a switchable diode effect in two-dimensional α-In2Se3 thin layers. Nanoscale2018, 10, 14885–14892.

  24. [24]

    Zhou J. D.; Zeng Q. S.; Lv D. H.; Sun L. F.; Niu, L.; Fu, W.; Liu F. C.; Shen Z. X.; Jin C. H.; Liu, Z. Controlled synthesis of high-quality monolayered α-In2Se3 via physical vapor deposition. Nano Lett. 2015, 15, 6400–6405.

  25. [25]

    Wan S. Y.; Li, Y.; Li, W.; Mao X. Y.; Wang, C.; Chen, C.; Dong J. Y.; Nie A. M.; Xiang J. Y.; Liu Z. Y. et al. Nonvolatile ferroelectric memory effect in ultrathin α-In2Se3. Adv. Funct. Mater. 2019, 29, 1808606.

  26. [26]

    Küpers, M.; Konze P. M.; Meledin, A.; Mayer, J.; Englert, U.; Wuttig, M.; Dronskowski, R. Controlled crystal growth of indium selenide, In2Se3, and the crystal structures of α-In2Se3. Inorg. Chem. 2018, 57, 11775–11781.

  27. [27]

    Dawber, M.; Chandra, P.; Littlewood P. B.; Scott J. F. Depolarization corrections to the coercive field in thin-film ferroelectrics. J. Phys.: Condens. Matter2003, 15, L393.

  28. [28]

    Jo J. Y.; Kim Y. S.; Noh T. W.; Yoon J. G.; Song T. K. Coercive fields in ultrathin BaTiO3 capacitors. Appl. Phys. Lett. 2006, 89, 232909.

  29. [29]

    Ducharme, S.; Fridkin V. M.; Bune A. V.; Palto S. P.; Blinov L. M.; Petukhova N. N.; Yudin S. G. Intrinsic ferroelectric coercive field. Phys. Rev. Lett. 2000, 84, 175.

  30. [30]

    Tao, X.; Gu, Y. Crystalline-crystalline phase transformation in two-dimensional In2Se3 thin layers. Nano Lett. 2013, 13, 3501–3505.

  31. [31]

    Liu J.; Pantelides S. T. Pyroelectric response and temperature-induced α–β phase transitions in α-In2Se3 and other α-III2VI3 (III = Al, Ga, In; VI = S, Se) monolayers. 2D Mater. 2018, 6, 025001.

  32. [32]

    Xu, B.; Xiang, H.; Xia Y. D.; Jiang, K.; Wan X. G.; He, J.; Yin, J.; Liu Z. G. Monolayer AgBiP2Se6: An atomically thin ferroelectric semiconductor with out-plane polarization. Nanoscale2017, 9, 8427–8434.

  33. [33]

    Gerra, G.; Tagantsev A. K.; Setter, N.; Parlinski, K. Ionic polarizability of conductive metal oxides and critical thickness for ferroelectricity in BaTiO3. Phys. Rev. Lett. 2006, 96, 107603.

  34. [34]

    Qiao H. M.; He, C.; Wang Z. J.; Pang D. F.; Li X. Z.; Liu, Y.; Long X. F. Influence of Mn dopants on the electrical properties of Pb(In0.5Nb0.5) O3-PbTiO3 ferroelectric single crystals. RSC Adv. 2017, 7, 32607–32612.

  35. [35]

    Zhang X. L.; Xu H. S.; Zhang Y. N. Temperature dependence of coercive field and fatigue in poly(vinylidene fluoride-trifluoroethylene) copolymer ultra-thin films. J. Phys. D: Appl. Phys. 2011, 44, 155501.

  36. [36]

    Luo, J.; Sun, W.; Zhou, Z.; Bai, Y.; Wang Z. J.; Tian, G.; Chen D. Y.; Gao X. S.; Zhu F. Y.; Li J. F. Domain evolution and piezoelectric response across thermotropic phase boundary in (K, Na) NbO3-based epitaxial thin films. ACS Appl. Mater. Interfaces2017, 9, 13315–13322.

  37. [37]

    Ho C. H. Amorphous effect on the advancing of wide-range absorption and structural-phase transition in γ-In2Se3 polycrystalline layers. Sci. Rep. 2014, 4, 4764.

  38. [38]

    Mbarki, R.; Haskins J. B.; Kinaci, A.; Cagin, T. Temperature dependence of flexoelectricity in BaTiO3 and SrTiO3 perovskite nanostructures. Phys. Lett. A2014, 378, 2181–2183.

  39. [39]

    Almahmoud, E.; Kornev, I.; Bellaiche, L. Dependence of Curie temperature on the thickness of an ultrathin ferroelectric film. Phys. Rev. B, 2010, 81, 064105.

  40. [40]

    Fong D. D.; Stephenson G. B.; Streiffer S. K.; Eastman J. A.; Auciello, O.; Fuoss P. H.; Thompson, C. Ferroelectricity in ultrathin perovskite films. Science2004, 304, 1650–1653.

  41. [41]

    Ishikawa, K.; Nomura, T.; Okada, N.; Takada, K. Size effect on the phase transition in PbTiO3 fine particles. Jpn. J. Appl. Phys. 1996, 35, 5196–5198.

  42. [42]

    Simon, A.; Ravez, J.; Maisonneuve, V.; Payen, C.; Cajipe V. B. Paraelectric-ferroelectric transition in the lamellar thiophosphate CuInP2S6. Chem. Mater. 1994, 6, 1575–1580.

Download references


This research was supported by the grant from Research Grants Council of Hong Kong (GRF No. PolyU 153033/17P).

Author information

Correspondence to Jianhua Hao.

Electronic Supplementary Material

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Io, W.F., Yuan, S., Pang, S.Y. et al. Temperature- and thickness-dependence of robust out-of-plane ferroelectricity in CVD grown ultrathin van der Waals α-In2Se3 layers. Nano Res. (2020).

Download citation


  • In2Se3
  • 2D materials
  • ferroelectricity
  • high-temperature
  • coercive field