Isolated monolayer thickness WSe2 are grown onto c-cut (0001) sapphire substrates. This particular product contains monolayer thickness WSe2 triangular flakes randomly distributed across sapphire substrate. While some regions reach continuity with coalesced WSe2 triangles, this sample contains well-separated triangles for advanced spectroscopy, microscopy, and electronic measurements. Synthesized monolayer WSe2 triangles are highly luminescent and Raman spectroscopy studies also confirm the monolayer thickness.
Sample Properties.
Sample size | 1cm x 1cm square shaped |
Substrate type | (0001) c-cut sapphire |
Coverage | Isolated and partially merged monolayer triangles |
Electrical properties | 1.62 eV Direct Bandgap Semiconductor |
Crystal structure | Hexagonal Phase |
Unit cell parameters | a = b = 0.327 nm, c = 1.295 nm, α = β = 90°, γ = 120° |
Production method | Low pressure Chemical Vapor Deposition (LPCVD) |
Characterization methods | Raman, photoluminescence, TEM, EDS |
Specifications
1) Well-separated WSe2 domains across c-cut sapphire
2) One centimeter in size. Larger sizes up to 2-inch wafer-scale available upon requests.
3) Atomically smooth surface with roughness < 0.22 nm.
4) Highly uniform surface morphology
5) 99.9995% purity as determined by nano-SIMS measurements
6) Repeatable Raman and photoluminescence response
7) High crystalline quality, Raman response, and photoluminescence emission comparable to single crystalline monolayer flakes.
8) c-cut Sapphire but our research and development team can transfer WSe2 triangles onto variety of substrates including PET, quartz, and SiO2/Si without significant compromising of material quality.
9) Defect profile. WSe2 monolayer triangles do not contain intentional dopants or defects. However, our technical staff can produce defected WSe2 using α-bombardment technique.
Supporting datasets [for * Full area coverage on SiO2/Si]
Transmission electron images (TEM) acquired from CVD grown WSe2 (triangular) monolayers on sapphire confirming highly crystalline nature of monolayers
Room temperature photoluminescence spectroscopy (PL) and Raman spectroscopy (Raman) measurements performed on CVD grown WSe2 triangle monolayers on c-cut sapphire. Raman spectroscopy measurement confirm monolayer nature of the CVD grown samples and PL spectrum display sharp and bright PL peak located at 1.62 eV in agreement with the literature.
