부산대학교 도서관

Molybdenum trioxide (MoO3) thin film layers have been deposited via wet-chemical spin coating technique. The suitability to obtain a highly crystalline and compact MoO3 thin films by a post-deposition annealing treatment is investigated. The most stable α-orthorhombic phase of MoO3 with preferential bragg reflection (002) was revealed with structural analysis. The energy bandgap decreased to the annealed samples from 3.05 to 2.92 eV is related to the particle size enhancement. The Raman peak exhibited at 819 cm−1 to 500 °C annealed layer was identified to (Mo–O–Mo) symmetric stretching mode (Ag). The surface morphology studied by FESEM confirms the presence of well-adherent, void-free, densely packed granules with a uniform size of particles suitable for making thin back contact buffer layers CdTe devices. Furthermore, all the samples were observed to be uniformly and densely deposited without voids over a larger area. Electrical measurements, current density-voltage and capacitance-voltage were performed to calculate the ideality factor (η), barrier height (Φb), carrier concentration and flat band potentials. The increase in carrier concentration with rising annealing temperature confirms the growth of low-defect MoO3 layers with enhanced crystallinity. The results reported herein are promising and may have potential role to develop low-resistive back contact to CdTe for photovoltaic devices.