MoSe2 Crystal

Our large size vdW MoSe2 crystals are treated as gold standards in 2D materials field. These MoSe2 vdW crystals are grown using two different techniques, namely chemical vapor transport (CVT) and Flux zone growth (Flux) to achieve impressive WS2 characteristics.

Flux grown: Mose2 crystals will exhibit superior electronic, valleytronic performance with perfect crystallization, defect free structure, extremely narrow PL bandwidths, clean PL spectra (free of bound exciton shoulders), and high carrier mobility.

CVT grown: These samples will be more comparable to other commercially available materials with some defects and lower electronic/optical quality but at slightly larger sizes. 

Status: In stock

20 years of growth optimization in chemical vapor transport (CVT) as well as flux growth lead to our flawless WS2 crystals: The only commercial MoSe2 crystals that come with guaranteed valleytronic and PL responses. 

Properties of single crystal vdW MoSe2 

Crystal size	~1cm in size
Dopants	Undoped (intrinsic semiconductor)
Material properties	1.56 eV emission (300K), direct gap semiconductor
Crystal structure	Hexagonal phase
Unit cell parameters	a=b=0.330 nm, c=1.292 nm; α=β=90°, γ=120°
Growth Method	[Default] Flux zone (no halide contamination) defect free [Optional CVT]: Contains Br2, Cl2, TeCl4, and other halides
Purity	99.9999% confirmed

 

Growth method matters> Flux zone or CVT growth method? Contamination of halides and point defects in layered crystals are well known cause for their reduced electronic mobility, reduced anisotropic response, poor e-h recombination, low-PL emission, and lower optical absorption. Flux zone technique is a halide free technique used for synthesizing truly semiconductor grade vdW crystals. This method distinguishes itself from chemical vapor transport (CVT) technique in the following regard: CVT is a quick (~2 weeks) growth method but exhibits poor crystalline quality and the defect concentration reaches to 1E11 to 1E12 cm-2 range. In contrast, flux method takes long (~3 months) growth time, but ensures slow crystallization for perfect atomic structuring, and impurity free crystal growth with defect concentration as low as 1E9 - 1E10 cm-2. During check out just state which type of growth process is preferred. Unless otherwise stated, 2Dsemiconductors ships Flux zone crystals as a default choice. 

http://meetings.aps.org/Meeting/MAR18/Session/K36.3

http://meetings.aps.org/Meeting/MAR17/Session/V1.14

XRD datasets collected from MoSe2

HRTEM image collected from MoSe2 crystals

Photoluminescence specturm collected from MoSe2 at 300K

 

Raman spectrum collected from MoSe2 sheets

 

Publications from this product 

Summary: Publications from MIT, Berkeley, Stanford, Rice, and Harvard teams at top journals like Nature, Nature Communications, Nano Letters, and Advanced Materials

J. Ye et.al. "Nonlinear dynamics of trions under strong optical excitation in monolayer MoSe2" Nature Scientific Reports, 8, 2389 (2018)

Control of Exciton Valley Coherence in Transition Metal Dichalcogenide Monolayers, Phys. Rev. Lett. 117, 187401 (2016)

Measurement of the optical dielectric function of monolayer transition-metal dichalcogenides: MoS2, MoSe2, WS2, and WSe2, Yilei Li, Alexey Chernikov, Xian Zhang, Albert Rigosi, Heather M. Hill, Arend M. van der Zande, Daniel A. Chenet, En-Min Shih, James Hone, and Tony F. Heinz; Phys. Rev. B 90, 205422 (2014)

Y. Jin "A Van Der Waals Homojunction: Ideal p–n Diode Behavior in MoSe2" Advanced Materials 27, 5534–5540 (2015)

Tongay et. al. "Defects activated photoluminescence in two-dimensional semiconductors: interplay between bound, charged, and free excitons" Scientific Reports 3, Article number: 2657 (2013)

M. Yankowitz et. al. "Intrinsic Disorder in Graphene on Transition Metal Dichalcogenide Heterostructures" Nano Letters, 2015, 15 (3), pp 1925–1929

Tongay et.al. Thermally Driven Crossover from Indirect toward Direct Bandgap in 2D Semiconductors: MoSe2 versus MoS2; Nano Letters, 2012, 12 (11), pp 5576–5580

Manish Chhowalla, "Two-dimensional semiconductors for transistors" Nature Reviews Materials 1, Article number: 16052 (2016) doi:10.1038/natrevmats.2016.52

X Li et al. "Determining layer number of twodimensional flakes of transition-metal dichalcogenides by the Raman intensity from substrates" Nanotechnology 27 (2016) 145704

L. Zhang. et.al. "Photonic-crystal exciton-polaritons in monolayer semiconductors" Nature Communications volume 9, Article number: 713 (2018)