Narrow excitonic lines and large-scale homogeneity of transition metal dichalcogenide monolayer grown by MBE on hBN.

Monolayer transition metal dichalcogenides (TMDs) manifest exceptional optical properties related to narrow excitonic resonances. However, these properties have been so far explored only for structures produced by techniques inducing considerable large-scale inhomogeneity. In contrast, techniques which are essentially free from this disadvantage, such as molecular beam epitaxy (MBE), have to date yielded only structures characterized by considerable spectral broadening, which hinders most of interesting optical effects. Here we report for the first time on the MBE-grown TMD exhibiting narrow and resolved spectral lines of neutral and charged exciton. Moreover, our material exhibits unprecedented high homogeneity of optical properties, with variation of the exciton energy as small as 0.16 meV over a distance of tens of micrometers. Our recipe for MBE growth is presented for MoSe2 and includes the use of atomically flat hexagonal boron nitride (hBN) substrate. This recipe opens a possibility of producing TMD heterostructures with optical quality, dimensions and homogeneity required for optoelectronic applications.

[1]  Kenji Watanabe,et al.  Momentum-forbidden dark excitons in hBN-encapsulated monolayer MoS2 , 2019, npj 2D Materials and Applications.

[2]  C. Robert,et al.  High optical quality of MoS2 monolayers grown by chemical vapor deposition , 2019, 2D Materials.

[3]  A. Ouerghi,et al.  Magneto-spectroscopy of exciton Rydberg states in a CVD grown WSe2 monolayer , 2019, Applied Physics Letters.

[4]  B. Grévin,et al.  Van der Waals solid phase epitaxy to grow large-area manganese-doped MoSe2 few-layers on SiO2/Si , 2019, 2D Materials.

[5]  A. Marty,et al.  van der Waals epitaxy of Mn-doped MoSe2 on mica , 2019, APL Materials.

[6]  M. Terrones,et al.  Defect-Controlled Nucleation and Orientation of WSe2 on hBN: A Route to Single-Crystal Epitaxial Monolayers. , 2019, ACS nano.

[7]  Young Hee Lee,et al.  Wafer-scale single-crystal hexagonal boron nitride film via self-collimated grain formation , 2018, Science.

[8]  S. Pennycook,et al.  Molecular Beam Epitaxy of Highly Crystalline MoSe2 on Hexagonal Boron Nitride. , 2018, ACS nano.

[9]  C. Robert,et al.  Spectrally narrow exciton luminescence from monolayer MoS2 and MoSe2 exfoliated onto epitaxially grown hexagonal BN , 2018, Applied Physics Letters.

[10]  R. Schmidt,et al.  Strain transfer across grain boundaries in MoS2 monolayers grown by chemical vapor deposition , 2018 .

[11]  J. Gupta,et al.  Room Temperature Intrinsic Ferromagnetism in Epitaxial Manganese Selenide Films in the Monolayer Limit. , 2018, Nano letters.

[12]  Chaofan Zhang,et al.  Electronic structure of monolayer 1T′-MoTe2 grown by molecular beam epitaxy , 2018 .

[13]  Gwo-Ching Wang,et al.  Diffusion-Controlled Epitaxy of Large Area Coalesced WSe2 Monolayers on Sapphire. , 2018, Nano letters.

[14]  Moon J. Kim,et al.  MBE growth of few-layer 2H-MoTe 2 on 3D substrates , 2017, 1705.00651.

[15]  Xiaotang Hu,et al.  Real-time monitoring of 2D semiconductor film growth with optical spectroscopy , 2017, Nanotechnology.

[16]  Vinayak P. Dravid,et al.  Substrate-induced strain and charge doping in CVD-grown monolayer MoS2 , 2017 .

[17]  M. Nakano,et al.  Layer-by-Layer Epitaxial Growth of Scalable WSe2 on Sapphire by Molecular Beam Epitaxy. , 2017, Nano letters.

[18]  Zijing Ding,et al.  Molecular Beam Epitaxy of Highly Crystalline Monolayer Molybdenum Disulfide on Hexagonal Boron Nitride. , 2017, Journal of the American Chemical Society.

[19]  R. Ruoff,et al.  Mechanical properties of atomically thin boron nitride and the role of interlayer interactions , 2017, Nature Communications.

[20]  Oriol López Sánchez,et al.  Highly Oriented Atomically Thin Ambipolar MoSe2 Grown by Molecular Beam Epitaxy , 2017, ACS Nano.

[21]  Kenji Watanabe,et al.  Direct exciton emission from atomically thin transition metal dichalcogenide heterostructures near the lifetime limit , 2017, Scientific Reports.

[22]  M. Terrones,et al.  Optical identification of sulfur vacancies: Bound excitons at the edges of monolayer tungsten disulfide , 2017, Science Advances.

[23]  D. Fu,et al.  Large Area Synthesis of 1D‐MoSe2 Using Molecular Beam Epitaxy , 2017, Advanced materials.

[24]  Kenji Watanabe,et al.  Approaching the intrinsic photoluminescence linewidth in transition metal dichalcogenide monolayers , 2017, 1702.05857.

[25]  A. Marty,et al.  Millimeter-scale layered MoSe 2 grown on sapphire and evidence for negative magnetoresistance , 2017, 1702.05121.

[26]  A. Kis,et al.  Micro-reflectance and transmittance spectroscopy: a versatile and powerful tool to characterize 2D materials , 2016, 1612.04145.

[27]  Kenji Watanabe,et al.  Molecular beam epitaxy growth of monolayer niobium diselenide flakes , 2016 .

[28]  M. Chou,et al.  Bandgap renormalization and work function tuning in MoSe2/hBN/Ru(0001) heterostructures , 2016, Nature Communications.

[29]  Yongqiang Yu,et al.  Ultrafast, Broadband Photodetector Based on MoSe2/Silicon Heterojunction with Vertically Standing Layered Structure Using Graphene as Transparent Electrode , 2016, Advanced science.

[30]  Moon J. Kim,et al.  Controllable growth of layered selenide and telluride heterostructures and superlattices using molecular beam epitaxy , 2016 .

[31]  S. Banerjee,et al.  Structural and Electrical Properties of MoTe2 and MoSe2 Grown by Molecular Beam Epitaxy. , 2016, ACS applied materials & interfaces.

[32]  H. J. Liu,et al.  Molecular-beam epitaxy of monolayer and bilayer WSe2: a scanning tunneling microscopy/spectroscopy study and deduction of exciton binding energy , 2015, 1506.04460.

[33]  J. L. Chen,et al.  Molecular-beam epitaxy of monolayer MoSe2: growth characteristics and domain boundary formation , 2015 .

[34]  Kenji Watanabe,et al.  Direct Growth of Single- and Few-Layer MoS2 on h-BN with Preferred Relative Rotation Angles. , 2015, Nano letters.

[35]  J. Warner,et al.  All Chemical Vapor Deposition Growth of MoS2:h-BN Vertical van der Waals Heterostructures. , 2015, ACS nano.

[36]  E. Palleau,et al.  Polarization and time-resolved photoluminescence spectroscopy of excitons in MoSe2 monolayers , 2015, 1502.03591.

[37]  Kenji Watanabe,et al.  Direct chemical vapor deposition growth of WS2 atomic layers on hexagonal boron nitride. , 2014, ACS nano.

[38]  Xiang Zhang,et al.  Edge Nonlinear Optics on a MoS2 Atomic Monolayer , 2014, Science.

[39]  Aaron M. Jones,et al.  Electrical control of neutral and charged excitons in a monolayer semiconductor , 2012, Nature Communications.

[40]  H. Zeng,et al.  Optical signature of symmetry variations and spin-valley coupling in atomically thin tungsten dichalcogenides , 2012, Scientific Reports.

[41]  Qing Hua Wang,et al.  Electronics and optoelectronics of two-dimensional transition metal dichalcogenides. , 2012, Nature nanotechnology.

[42]  K. Shepard,et al.  Boron nitride substrates for high-quality graphene electronics. , 2010, Nature nanotechnology.

[43]  W. Mccray,et al.  MBE deserves a place in the history books. , 2007, Nature nanotechnology.

[44]  K. Novoselov,et al.  Two-dimensional atomic crystals. , 2005, Proceedings of the National Academy of Sciences of the United States of America.

[45]  B. Parkinson,et al.  van der Waals epitaxial growth and characterization of MoSe2 thin films on SnS2 , 1990 .

[46]  M. Panish.  Molecular-beam epitaxy , 1989, AT&T Technical Journal.