TaWSe2 Crystal

Layered TaWSe2 ternary alloys have been synthesized at 50%-50% W (tungsten) to Ta (tantalum) ratios. While WSe2 is a direct gap semiconductor with high excitonic binding energy and valleytronic properties, 2H-TaSe2 is a metal with charge density waves (incommensurate CDW). It has superconducting transition at around below 1K. These two extreme compositions were alloyed to create 1:1 W:Ta ratio vdW crystals. These crystals are completely new to the community in the bulk as well as monolayer form and many of its properties are awaiting to be explored.

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.