Synthesis of MoS2/MoO3 compound thin films using spray pyrolysis technique and investigation on annealing treatment effect on their physical properties

In this research the effect of substrate temperature and also annealing treatment at sulfur atmosphere on structural, surface morphological, optical, electrical and thermoelectrical properties of molybdenum trioxide/molybdenum disulfide (MoS2/MoO3) compound thin films were studied. The XRD patterns analysis indicated the formation of crystallite structure with two MoO3 orthorhombic and MoS2 hexagonal phases. After sulfurization process, the peaks of oxide phase disappeared and MoS2 single phase structure formed. FESEM images indicated surfaces that was coated uniformly with spherical shaped particles. All samples had an absorption coefficient about 104 cm-1 and their band gap energy after sulfurization significantly reduces in average from 2.60 to 1.55 eV. Hall effect data showed that MoS2 thin films had hole conduction type (in agreement to trend of variation of Seebeck coefficient) and also hole density in order of 1015 cm-3.