Graphical Abstract

Van der Waals (vdW) heterojunctions are equipped to avert dangling bonds due to weak, inter-layer vdW force, and ensure strong in-plane covalent bonding for two-dimensional layered structures. We fabricated four heterojunctions devices of different layers based on p-type distorted 1T-MX2 ReSe2 and n-type hexagonal MoS2 nanoflakes, and measured their electronic and optoelectronic properties. The device showed a high rectification coefficient of 500 for the diode, a high ON/OFF ratio and higher electron mobility for the field-effect transistor (FET) compared with the individual components, and a high current responsivity (Rλ) and external quantum efficiency (EQE) of 6.75 A/W and 1, 266%, respectively, for the photodetector.
Dean, C.; Young, A. F.; Wang, L.; Meric, I.; Lee, G. H.; Watanabe, K.; Taniguchi, T.; Shepard, K.; Kim, P.; Hone, J. Graphene based heterostructures. Solid State Commun. 2012, 152, 1275-1282.
Lee, C. H.; Lee, G. H.; van der Zande, A. M.; Chen, W. C.; Li, Y. L.; Han, M. Y.; Cui, X.; Arefe, G.; Nuckolls, C.; Heinz, T. F. et al. Atomically thin p-n junctions with van der waals heterointerfaces. Nat. Nanotechnol. 2014, 9, 676-681.
Zhang, Y. J.; Dong, H. L.; Tang, Q. X.; Ferdous, S.; Liu, F.; Mannsfeld, S. C. B.; Hu, W. P.; Briseno, A. L. Organic single-crystalline p-n junction nanoribbons. J. Am. Chem. Soc. 2010, 132, 11580-11584.
Fang, H.; Battaglia, C.; Carraro, C.; Nemsak, S.; Ozdol, B.; Kang, J. S.; Bechtel, H. A.; Desai, S. B.; Kronast, F.; Unal, A. A. et al. Strong interlayer coupling in van der waals heterostructures built from single-layer chalcogenides. Proc. Natl. Acad. Sci. USA 2014, 111, 6198-6202.
Tongay, S.; Zhou, J.; Ataca, C.; Lo, K.; Matthews, T. S.; Li, J. B.; Grossman, J. C.; Wu, J. Q. Thermally driven crossover from indirect toward direct bandgap in 2D semiconductors: MoSe2 versus MoS2. Nano Lett. 2012, 12, 5576-5580.
Zhu, C. F.; Zeng, Z. Y.; Li, H.; Li, F.; Fan, C. H.; Zhang, H. Single-layer MoS2-based nanoprobes for homogeneous detection of biomolecules. J. Am. Chem. Soc. 2013, 135, 5998-6001.
Zhou, K. -G.; Zhao, M.; Chang, M. -J.; Wang, Q.; Wu, X. -Z.; Song, Y. L.; Zhang, H. -L. Size-dependent nonlinear optical properties of atomically thin transition metal dichalcogenide nanosheets. Small 2015, 11, 694-701.
Fan, C.; Li, T.; Wei, Z. M.; Huo, N. J.; Lu, F. Y.; Yang, J. H.; Li, R. X.; Yang, S. X.; Li, B.; Hu, W. P. et al. Novel micro-rings of molybdenum disulfide (MoS2). Nanoscale 2014, 6, 14652-14656.
Yang, S. X.; Tongay, S.; Yue, Q.; Li, Y. T.; Li, B.; Lu, F. Y. High-performance few-layer Mo-doped ReSe2 nanosheet photodetectors. Sci. Rep. 2014, 4, 5442.
Yang, S. X.; Tongay, S.; Li, Y.; Yue, Q.; Xia, J. B.; Li, S. S.; Li, J. B.; Wei, S. H. Layer-dependent electrical and optoelectronic responses of ReSe2 nanosheet transistors. Nanoscale 2014, 6, 7226-7231.
Yang, S. X.; Wang, C.; Sahin, H.; Chen, H.; Li, Y.; Li, S. S.; Suslu, A.; Peeters, F. M.; Liu, Q.; Li, J. B. et al. Tuning the optical, magnetic, and electrical properties of ReSe2 by nanoscale strain engineering. Nano Lett. 2015, 15, 1660-1666.
Cui, G. L.; Zhang, M. Z.; Zou, G. T. Resonant tunneling modulation in quasi-2D Cu2O/SnO2 p-n horizontal-multi-layer heterostructure for room temperature H2S sensor application. Sci. Rep. 2013, 3, 1250.
Mak, K. F.; Lee, C.; Hone, J.; Shan, J.; Heinz, T. F. Atomically thin MoS2: A new direct-gap semiconductor. Phys. Rev. Lett. 2010, 105, 136805.
Yu, W. J.; Li, Z.; Zhou, H. L.; Chen, Y.; Wang, Y.; Huang, Y.; Duan, X. F. Vertically stacked multi-heterostructures of layered materials for logic transistors and complementary inverters. Nat. Mater. 2013, 12, 246-252.
Yu, W. J.; Liu, Y.; Zhou, H. L.; Yin, A. X.; Li, Z.; Huang, Y.; Duan, X. F. Highly efficient gate-tunable photocurrent generation in vertical heterostructures of layered materials. Nat. Nanotechnol. 2013, 8, 952-958.
Liang, L. B.; Meunier, V. First-principles Raman spectra of MoS2, WS2 and their heterostructures. Nanoscale 2014, 6, 5394-5401.
Radisavljevic, B.; Radenovic, A.; Brivio, J.; Giacometti, V.; Kis, A. Single-layer MoS2 transistors. Nat. Nanotechnol. 2011, 6, 147-150.
Wang, Z. X.; Xu, K.; Li, Y. C.; Zhan, X. Y.; Safdar, M.; Wang, Q. S.; Wang, F. M.; He, J. Role of Ga vacancy on a multilayer GaTe phototransistor. ACS Nano 2014, 8, 4859-4865.
Xu, K.; Wang, Z. X.; Du, X. L.; Safdar, M.; Jiang, C.; He, J. Atomic-layer triangular WSe2 sheets: Synthesis and layer-dependent photoluminescence property. Nanotechnology 2013, 24, 465705.
Wang, Z. X.; Safdar, M.; Mirza, M.; Xu, K.; Wang, Q. S.; Huang, Y.; Wang, F. M.; Zhan, X. Y.; He, J. High-performance flexible photodetectors based on GaTe nanosheets. Nanoscale 2015, 7, 7252-7258.
Haigh, S. J.; Gholinia, A.; Jalil, R.; Romani, S.; Britnell, L.; Elias, D. C.; Novoselov, K. S.; Ponomarenko, L. A.; Geim, A. K.; Gorbachev, R. Cross-sectional imaging of individual layers and buried interfaces of graphene-based heterostructures and superlattices. Nat. Mater. 2012, 11, 764-767.
Hong, X. P.; Kim, J.; Shi, S. F.; Zhang, Y.; Jin, C. H.; Sun, Y. H.; Tongay, S.; Wu, J. Q.; Zhang, Y. F.; Wang, F. Ultrafast charge transfer in atomically thin MoS2/WS2 heterostructures. Nat. Nanotechnol. 2014, 9, 682-686.
Tongay, S.; Fan, W.; Kang, J.; Park, J.; Koldemir, U.; Suh, J.; Narang, D. S.; Liu, K.; Ji, J.; Li, J. B. et al. Tuning interlayer coupling in large-area heterostructures with CVD-grown MoS2 and WS2 monolayers. Nano Lett. 2014, 14, 3185-3190.
Geim, A. K.; Grigorieva, I. V. Van der waals heterostructures. Nature 2013, 499, 419-425.
Ho, C. H.; Huang, Y. S.; Chen, J. L.; Dann, T. E.; Tiong, K. K. Electronic structure of ReS2 and ReSe2 from first-principles calculations, photoelectron spectroscopy, and electrolyte electroreflectance. Phys. Rev. B 1999, 60, 15766-15771.
Kang, J.; Li, J. B.; Li, S. S.; Xia, J. B.; Wang, L. W. Electronic structural moiré pattern effects on MoS2/MoSe2 2D heterostructures. Nano Lett. 2013, 13, 5485-5490.
Friemelt, K.; Lux-Steiner, M. -Ch.; Bucher, E. Optical properties of the layered transition-metal-dichalcogenide ReS2: Anisotropy in the van der Waals plane. J. Appl. Phys. 1993, 74, 5266-5268.
Cheng, R.; Li, D. H.; Zhou, H. L.; Wang, C.; Yin, A. X.; Jiang, S.; Liu, Y.; Chen, Y.; Huang, Y.; Duan, X. F. Electroluminescence and photocurrent generation from atomically sharp WSe2/MoS2 heterojunction p-n diodes. Nano Lett. 2014, 14, 5590-5597.
Lei, S. D.; Sobhani, A.; Wen, F. F.; George, A.; Wang, Q. Z.; Huang, Y. H.; Dong, P.; Li, B.; Najmaei, S.; Bellah, J. et al. Ternary CuIn7Se11: Towards ultra-thin layered photodetectors and photovoltaic devices. Adv. Mater. 2014, 26, 7666-7672.
Furchi, M. M.; Pospischil, A.; Libisch, F.; Burgdörfer, J.; Mueller, T. Photovoltaic effect in an electrically tunable van der Waals heterojunction. Nano Lett. 2014, 14, 4785-4791.
Yin, Z. Y.; Li, H.; Li, H.; Jiang, L.; Shi, Y. M.; Sun, Y. H.; Lu, G.; Zhang, Q.; Chen, X. D.; Zhang, H. Single-layer MoS2 phototransistors. ACS Nano 2012, 6, 74-80.
Fang, X. S.; Hu, L. F.; Huo, K. F.; Gao, B.; Zhao, L. J.; Liao, M. Y.; Chu, P. K.; Bando, Y.; Golberg, D. New ultraviolet photodetector based on individual Nb2O5 nanobelts. Adv. Funct. Mater. 2011, 21, 3907-3915.
Hu, P. A.; Wen, Z. Z.; Wang, L. F.; Tan, P. H.; Xiao, K. Synthesis of few-layer GaSe nanosheets for high performance photodetectors. ACS Nano 2012, 6, 5988-5994.
Huo, N. J.; Kang, J.; Wei, Z. M.; Li, S. -S.; Li, J. B.; Wei, S. -H. Novel and enhanced optoelectronic performances of multilayer MoS2-WS2 heterostructure transistors. Adv. Funct. Mater. 2014, 24, 7025-7031.
Tsai, D. -S.; Liu, K. -K.; Lien, D. -H.; Tsai, M. -L.; Kang, C. -F.; Lin, C. -A.; Li, L. -J.; He, J. -H. Few-layer MoS2 with high broadband photogain and fast optical switching for use in harsh environments. ACS Nano 2013, 7, 3905-3911.
Huo, N.; Yang, S.; Wei, Z.; Li, S. -S.; Xia, J. -B.; Li, J. Photoresponsive and gas sensing field-effect transistors based on multilayer WS2 nanoflakes. Sci. Rep. 2014, 4, 5209.
Hafner, J. Ab-initio simulations of materials using VASP: Density-functional theory and beyond. J. Comput. Chem. 2008, 29, 2044-2078.
Perdew, J. P.; Burke, K.; Ernzerhof, M. Generalized gradient approximation made simple. Phys. Rev. Lett. 1996, 77, 3865-3868.
Jiang, L. L.; Wu, B.; Liu, H. T.; Huang, Y.; Chen, J. Y.; Geng, D. C.; Gao, H. J.; Liu, Y. Q. A general approach for fast detection of charge carrier type and conductivity difference in nanoscale materials. Adv. Mater. 2013, 25, 7015-7019.
Doghish, M. Y.; Ho, F. D. A comprehensive analytical model for metal-insulator-semiconductor (MIS) devices: A solar-cell application. IEEE Trans. Electron Devices 1993, 40, 1446-1454.
Tran, D. P.; Macdonald, T. J.; Wolfrum, B.; Stockmann, R.; Nann, T.; Offenhäusser, A.; Thierry, B. Photoresponsive properties of ultrathin silicon nanowires. Appl. Phys. Lett. 2014, 105, 231116.
Wang, Q. H.; Kalantar-Zadeh, K.; Kis, A.; Coleman, J. N.; Strano, M. S. Electronics and optoelectronics of two-dimensional transition metal dichalcogenides. Nat. Nanotechnol. 2012, 7, 699-712.
Wang, Y. J.; Wang, Q. S.; Zhan, X. Y.; Wang, F. M.; Safdar, M.; He, J. Visible light driven type Ⅱ heterostructures and their enhanced photocatalysis properties: A review. Nanoscale 2013, 5, 8326-8339.