Analysis Of Structural And Optical Properties Of ZnO Thin Films By PLD

ZnO is a semiconductor material with wide direct band gap of 3.37eV and a large exciton binding energy of 60meV at room temperature. Theoretically, it can realize stimulated UV emission at RT. ZnO is also an ascendant piezoelectric, gas sensitive and optoelectronic material. There are many growth methods for ZnO films such as magnetron sputtering, chemical vapor deposition, sog-gel, spay pyrolysis, thermal oxidation and molecular beam epitaxy. Recently, new growth methods such as pulsed laser deposition, metal organic chemical vapor deposition, atomic layer epitaxy and laser molecular beam epitaxy have been widely used. Because ZnO has so many advantages in structure and property and has many growth methods, it can suit many different demands in component preparation. ZnO can be used to fabricate transparency electrode, piezoresistor, cell battery window, surface acoustic wave device, gas sensor and light-emitting diode etc.. In short wave region, ZnO can be used to fabricated UV light emitting and UV laser devices, and which is very important for improvement of memory density and optical information access speed. Pulsed laser deposition is a newly developed film growth technique. In this technique, high density laser ablates the target and produces ZnO plume depositing on heated substrate in high vacuum background. In this paper, ZnO films were prepared at various temperatures, laser frequencies and oxygen pressures. The films were examined by RHEED, XRD, PL, SEM, AFM, surface profiler and electronic probe. Through the research of the structural and optical properties of ZnO films, optimized conditions for growing ZnO films were obtained. The results suggested that high quality ZnO films with highly c-axis can be prepared by PLD.