14 years of growth optimization in chemical vapor transport (CVT) as well as flux growth lead to our flawless WS2 crystals: The only commercial WS2 crystals that come with guaranteed valleytronic and PL responses. Our large size vdW WS2 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. WS2 crystals from 2Dsemiconductors are known for its superior valleytronic performance, perfect crystallization, defect free structure, extremely narrow PL bandwidths, clean PL spectra (free of bound exciton shoulders), and high carrier mobility. Thousands of scientific articles have cited us and used these crystals for scientific accuracy and clean signals.