Dependence of the absorption and optical surface plasmon scattering of MoS₂ nanoparticles on aspect ratio, size, and media

The optical and electronic properties of suspensions of inorganic fullerene-like nanoparticles of MoS₂ are studied through light absorption and zeta-potential measurements and compared to those of the corresponding microscopic platelets. The total extinction measurements show that, in addition to excitonic peaks and the indirect band gap transition, a new peak is observed at 700-800 nm. This spectral peak has not been reported previously for MoS₂. Comparison of the total extinction and decoupled absorption spectrum indicates that this peak largely originates from scattering. Furthermore, the dependence of this peak on nanoparticle size, shape, and surface charge, as well as solvent refractive index, suggests that this transition arises from a plasmon resonance.