Optical and Structural Characterization of ZnO Films Deposited by Chemical Bath and Activated by means of Microwaves

摘要

Zinc oxide (ZnO) is a direct, wide band gap semiconductor material having many promising properties for UV/blue optoelectronics, transparent electronics, spintronic devices and sensor applications. The ZnO is synthesized by the technique of Chemical Bath Deposition by microwaves heating (MW-CBD). The urea concentration in the solution is varied, maintaining constant the zinc nitrate in ratio 1:1 ... 1:10. The physical properties of ZnO thin films were examined by X-ray diffraction (XRD), SEM-EDS, and Raman scattering, which are convenient tools that can provide us with plenty of information about crystal structure and elementary excitons. By X-rays one obtains that it has hexagonal polycrystalline wurtzite type structure. The IR absorption line at 3577 cm~(-1) detected at 300 K in bath chemical ZnO is assigned an O-H bond primarily aligned with the c-axis of the crystal and bonding between Zn-0 (473cm~(-1), 532 cm~(-1)). The Raman spectra show the first order experimental Raman spectra of ZnO excited by 514.5 nm laser line. The first order Raman modes A_(1T), E_(1T), E_2(H), A_(1L)and E_(1L) are identified as the peaks sited at 385,426,437, 572 and 584 cm~(-1)