Pacific Rim Symposium on Surfaces, Coatings and Interfaces (PacSurf 2016)
    Energy Harvesting & Storage Wednesday Sessions
       Session EH-WeE

Paper EH-WeE1
Influence of Annealing Treatment on Optical, Electric and Thermoelectric Properties of MBE Grown ZnO

Wednesday, December 14, 2016, 5:40 pm, Room Lehua

Session: Surfaces & Interfaces for Efficient Power Conversion
Presenter: Khalid Mahmood, Government College University Faisalabad, Pakistan
Correspondent: Click to Email
In this paper, we have reported the influence of annealing temperature and annealing environment on optical, electrical and thermoelectric properties of MBE grown ZnO thin films on Si substrate. A set of grown ZnO thin films was annealed in oxygen environment at 500oC – 800oC with a step of 1000C and another set was annealed in different environments (vacuum, oxygen, zinc and successively annealed vacuum and zinc) for one hour in a programmable furnace. Room temperature Seekbeck measurements showed that Seebeck coefficient and power factor increased from 222 to 510 µV/K and 8.8×10-6 to 2.6×10-4 Wm-1K-2 as annealing temperature increased from 500 to 800 0C respectively. This observation was related with the improvement of crystal structure of grown films with annealing temperature. X-ray diffraction (XRD) results demonstrated that full width half maximum (FWHM) of ZnO (002) plane decreased and crystalline size increased as the annealing temperature increased. Photoluminescence study revealed that the intensity of band edge emission increased and defect emission decreased as annealing temperature increased because the density of oxygen vacancy related donor defects decreased with annealing temperature. This argument was further justified by the Hall measurements which showed a decreasing trend of carrier concentration with annealing temperature