WSe2 is a semiconductor with an indirect band gap of 1.25 eV in the bulk and 1.62 eV direct optical band gap semiconductor in the monolayer form. Its electronic (single particle) band gap is located at ~2.0 eV with an excitonic binding energy of 0.4 eV. WSe2 layers are stacked together via van der Waals (vdW) interactions which enables them to be exfoliated down to monolayers. Our large size vdW WSe2 crystals are treated as gold standards in 2D materials field. The flux zone crystals measure ~5mm in size where as CVT crystals can reach to 1cm combined sizes.