Abstract
Anisotropic materials are of considerable interest because of their unique combination of polarization- or direction-dependent electrical, optical, and thermoelectric properties. Low-symmetry two-dimensional (2D) materials formed by van der Waals stacking of covalently bonded atomic layers are inherently anisotropic. Layered SnSe exhibits a low degree of lattice symmetry, with a distorted NaCl structure and an in-plane anisotropy. Here we report a systematic study of the in-plane anisotropic properties in layered SnSe, using angle-resolved Raman scattering, optical absorption, and electrical transport studies. The optical and electrical characterization was direction-dependent, and successfully identified the crystalline orientation in the layered SnSe. Furthermore, the dependence of Raman-intensity anisotropy on the SnSe flake thickness and the excitation wavelength were investigated by both experiments and theoretical calculations. Finally, the electrical transport studies demonstrated that few-layer SnSe field-effect transistors (FETs) have a large anisotropic ratio of carrier mobility (∼5.8) between the armchair and zigzag directions, which is a record high value reported for 2D anisotropic materials. The highly-anisotropic properties of layered SnSe indicate considerable promise for anisotropic optics, electronics, and optoelectronics.
Article PDF
Similar content being viewed by others
Explore related subjects
Discover the latest articles, news and stories from top researchers in related subjects.Avoid common mistakes on your manuscript.
References
Liu, E. F.; Fu, Y. J.; Wang, Y. J.; Feng, Y. Q.; Liu, H. M.; Wan, X. G.; Zhou, W.; Wang, B. G.; Shao, L. B.; Ho, C. H. et al. Integrated digital inverters based on two-dimensional anisotropic ReS2 field-effect transistors. Nat. Commun. 2014, 6, 6991.
Qiao, X. F.; Wu, J. B.; Zhou, L. W.; Qiao, J. S.; Shi, W.; Chen, T.; Zhang, X.; Zhang, J.; Ji, W.; Tan, P. H. Polytypism and unexpected strong interlayer coupling in two-dimensional layered ReS2. Nanoscale 2016, 8, 8324–8332.
Tao, J.; Shen, W. F.; Wu, S.; Liu, L.; Feng, Z. H.; Wang, C.; Hu, C. G.; Yao, P.; Zhang, H.; Pang, W. et al. Mechanical and electrical anisotropy of few-layer black phosphorus. ACS Nano 2015, 9, 11362–11370.
Chenet, D. A.; Aslan, O. B.; Huang, P. Y.; Fan, C.; van der Zande, A. M.; Heinz, T. F.; Hone, J. C. In-plane anisotropy in mono- and few-layer ReS2 probed by raman spectroscopy and scanning transmission electron microscopy. Nano Lett. 2015, 15, 5667–5672.
Hart, L.; Dale, S.; Hoye, S.; Webb, J. L.; Wolverson, D. Rhenium dichalcogenides: Layered semiconductors with two vertical orientations. Nano Lett. 2016, 16, 1381–1386.
Zhao, H.; Wu, J. B.; Zhong, H. X.; Guo, Q. S.; Wang, X. M.; Xia, F. N.; Yang, L.; Tan, P. H.; Wang, H. Interlayer interactions in anisotropic atomically thin rhenium diselenide. Nano Res. 2015, 8, 3651–3661.
Hafeez, M.; Gan, L.; Li, H. Q.; Ma, Y.; Zhai, T. Y. Chemical vapor deposition synthesis of ultrathin hexagonal ReSe2 flakes for anisotropic Raman property and optoelectronic application. Adv. Mater. 2016, 28, 8296–8301.
Ali, M. N.; Xiong, J.; Flynn, S.; Tao, J.; Gibson, Q. D.; Schoop, L. M.; Liang, T.; Haldolaarachchige, N.; Hirschberger, M.; Ong, N. P. et al. Large, non-saturating magnetoresistance in WTe2. Nature 2014, 514, 205–208.
Wang, C.; Yang, S. X.; Xiong, W. Q.; Xia, C. X.; Cai, H.; Chen, B.; Wang, X. T.; Zhang, X. Z.; Wei, Z. M.; Tongay, S. et al. Gate-tunable diode-like current rectification and ambipolar transport in multilayer van der Waals ReSe2/WS2 p–n heterojunctions. Phys. Chem. Chem. Phys. 2016, 18, 27750–27753.
Ribeiro, H. B.; Pimenta, M. A.; de Matos, C. J. S.; Moreira, R. L.; Rodin, A. S.; Zapata, J. D.; de Souza, E. A. T.; Neto, A. H. C. Unusual angular dependence of the Raman response in black phosphorus. ACS Nano 2015, 9, 4270–4276.
Zhao, L. D.; Tan, G. J.; Hao, S. Q.; He, J. Q.; Pei, Y. L.; Chi, H.; Wang, H.; Gong, S. K.; Xu, H. B.; Dravid, V. P. et al. Ultrahigh power factor and thermoelectric performance in hole-doped single-crystal SnSe. Science 2016, 351, 141–144.
Safdar, M.; Wang, Q. S.; Mirza, M.; Wang, Z. X.; Xu, K.; He, J. Topological surface transport properties of singlecrystalline SnTe nanowire. Nano Lett. 2013, 13, 5344–5349.
Huang, S. X.; Tatsumi, Y.; Ling, X.; Guo, H. H.; Wang, Z. Q.; Watson, G.; Puretzky, A. A.; Geohegan, D. B.; Kong, J.; Li, J. et al. In-plane optical anisotropy of layered gallium telluride. ACS Nano 2016, 10, 8964–8972.
Wu, J. X.; Mao, N. N.; Xie, L. M.; Xu, H.; Zhang, J. Identifying the crystalline orientation of black phosphorus using angle-resolved polarized Raman spectroscopy. Angew. Chem., Int. Ed. 2015, 54, 2366–2369.
Wang, C.; Yang, S. X.; Cai, H.; Ataca, C.; Chen, H.; Zhang, X. Z.; Xu, J. J.; Chen, B.; Wu, K. D.; Zhang, H. R. et al. Enhancing light emission efficiency without color change in post-transition metal chalcogenides. Nanoscale 2016, 8, 5820–5825.
Yang, S. X.; Wang, C.; Ataca, C.; Li, Y.; Chen, H.; Cai, H.; Suslu, A.; Grossman, J. C.; Jiang, C. B.; Liu, Q. et al. Selfdriven photodetector and ambipolar transistor in atomically thin GaTe-MoS2 p−n vdW heterostructure. ACS Appl. Mater. Interfaces 2016, 8, 2533–2539.
Ling, X.; Huang, S. X.; Hasdeo, E. H.; Liang, L. B.; Parkin, W. M.; Tatsumi, Y.; Nugraha, A. R. T.; Puretzky, A. A.; Das, P. M.; Sumpter, B. G. et al. Anisotropic electron–photon and electron–phonon interactions in black phosphorus. Nano Lett. 2016, 16, 2260–2267.
Tian, H.; Guo, Q. S.; Xie, Y. J.; Zhao, H.; Li, C.; Cha, J. J.; Xia, F. N.; Wang, H. Anisotropic black phosphorus synaptic device for neuromorphic applications. Adv. Mater. 2016, 28, 4991–4997.
Xue, D. J.; Tan, J. H.; Hu, J. S.; Hu, W. P.; Guo, Y. G.; Wan, L. J. Anisotropic photoresponse properties of single micrometer-sized GeSe nanosheet. Adv. Mater. 2012, 24, 4528–4533.
Ge, S. F.; Li, C. K.; Zhang, Z. M.; Zhang, C. L.; Zhang, Y. D.; Qiu, J.; Wang, Q. S.; Liu, J. K.; Jia, S.; Feng, J. et al. Dynamical evolution of anisotropic response in black phosphorus under ultrafast photoexcitation. Nano Lett. 2015, 15, 4650–4656.
Xia, F. N.; Wang, H.; Jia, Y. C. Rediscovering black phosphorus as an anisotropic layered material for optoelectronics and electronics. Nat. Commun. 2014, 5, 4458.
Zhao, S. L.; Wang, H.; Zhou, Y.; Liao, L.; Jiang, Y.; Yang, X.; Chen, G. C.; Lin, M.; Wang, Y.; Peng, H.L. et al. Controlled synthesis of single-crystal SnSe nanoplates. Nano Res. 2015, 8, 288–295.
Zhao, L. D.; Lo, S. H.; Zhang, Y. S.; Sun, H.; Tan, G. J.; Uher, C.; Wolverton, C.; Dravid, V. P.; Kanatzidis, M. G. Ultralow thermal conductivity and high thermoelectric figure of merit in SnSe crystals. Nature 2014, 508, 373–377.
Antunez, P. D.; Buckley, J. J.; Brutchey, R. L. Tin and germanium monochalcogenide IV–VI semiconductor nanocrystals for use in solar cells. Nanoscale 2011, 3, 2399–2411.
Vaughn II, D. D.; In, S. I.; Schaak, R. E. A precursorlimited nanoparticle coalescence pathway for tuning the thickness of laterally-uniform colloidal nanosheets: The case of SnSe. ACS Nano 2011, 5, 8852–8860.
Pejova, B.; Tanuševsk, A. A Study of photophysics, photoelectrical properties, and photoconductivity relaxation dynamics in the case of nanocrystalline Tin(II) selenide thin films. J. Phys. Chem. C 2008, 112, 3525–3537.
Agarwal, A.; Vashi, M. N.; Lakshminarayana, D.; Batra, N. M. Electrical resistivity anisotropy in layered p-SnSe single crystals. J. Mater. Sci. Mater. Electron. 2000, 11, 67–71.
Shi, G. S.; Kioupakis, E. Anisotropic spin transport and strong visible-light absorbance in few-layer SnSe and GeSe. Nano Lett. 2015, 15, 6926–6931.
Li, L.; Chen, Z.; Hu, Y.; Wang, X. W.; Zhang, T.; Chen, W.; Wang, Q. B. Single-layer single-crystalline SnSe nanosheets. J. Am. Chem. Soc. 2013, 135, 1213–1216.
Carrete, J.; Mingo, N.; Curtarolo, S. Low thermal conductivity and triaxial phononic anisotropy of SnSe. Appl. Phys. Lett. 2014, 105, 101907.
Zhang, J.; Zhu, H. Y.; Wu, X. X.; Cui, H.; Li, D. M.; Jiang, J. R.; Gao, C. X.; Wang, Q. S.; Cui, Q. L. Plasma-assisted synthesis and pressure-induced structural transition of singlecrystalline SnSe nanosheets. Nanoscale 2015, 7, 10807–10816.
Das, S.; Demarteau, M.; Roelofs, A. Ambipolar phosphorene field effect transistor. ACS Nano 2014, 8, 11730–11738.
Wu, J. B.; Zhao, H.; Li, Y. R.; Ohlberg, D.; Shi, W.; Wu, W.; Wang, H.; Tan, P. H. Monolayer molybdenum disulfide nanoribbons with high optical anisotropy. Adv. Opt. Mater. 2016, 4, 756–762.
Acknowledgements
We thank the support from National Science Foundation through the grant DMR1508144. S. X. Y. is supported by the National Natural Science Foundation of China (No. 51602014) and Fundamental Research Funds for the Central Universities (No. YWF-17-BJ-Y-112). C. B. J. is supported by the National Natural Science Foundations of China (No. 51331001). S. H. W. is supported by the National Natural Science Foundations of China (No. 51672023). We thank Prof. Dehui Li for discussing the experiments and related data.
Author information
Authors and Affiliations
Corresponding authors
Electronic supplementary material
Rights and permissions
About this article
Cite this article
Yang, S., Liu, Y., Wu, M. et al. Highly-anisotropic optical and electrical properties in layered SnSe. Nano Res. 11, 554–564 (2018). https://doi.org/10.1007/s12274-017-1712-2
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12274-017-1712-2