Optical, electro-optical and transport properties of MoS2

Optical and transport properties of natural and synthetic crystals of 2H-MoS2 have been investigated by infra-red absorption at 300 K, conventional reflectivity, modulation reflectivity (wave-length, electric field and thermal)in the visible region at 85 K and temperature dependence of resistivity in the range (295-850) K. Five independent exciton series were observed in which the first series forms a hydrogen-like sequence. Three absorption bands occur in transmission spectrum in addition to the absorption edge at approx. 1 μ m. Resistivity measurements showed extrinsic semiconductor behaviour below 750 K, becoming intrinsic above 750 K with an activation energy of 1.2 eV. The optical and transport results are consistent with the band structure calculation by linear combination of the muffin-tin orbital method