Second Harmonic Generation of Transition Metal Dichalcogenide and BNC Alloys

The advances in growth methods is allowing the possibility of synthesizing alloys of 2-D materials: To shed light on their nonlinear optical properties, first principles calculations have been used to calculate the second harmonic generation (SHG) of alloys of transition metal dichalcogenides (TMDS) and BNC layered systems. The results obtained indicate that chalcogen alloys of the type MoSSe or WSSe are more suitable for SHG applications than alloys of the type MoWS₄ or MoWSe₄. Additionally, zigzag nanotubes made from the above mentioned alloys have been considered and it is found that as their diameter gets smaller the intensity of the SHG is higher. Surpisingly, the intensity of the SHG in TMDs Haeckelites of the type NbSSe and Nb_0.5Ta_0.5S₂ exhibit the highest intensity for the SHG. The study was extended to BNC alloy systems of the type BNC₂, B_xN_xC_y Haeckelites and porous BN (BN Schwarzites). It is found that BNC₂ possesses much higher SHG than h-BN, making this a suitable material for non-linear optical properties. BN Schwarzites can be compared with the highest SHG 3-D materials found so far.