Optical and Electrical Properties of ZnO:Eu Thin Films grown by Pulsed Laser Deposition

• Main Authors: Yang Shih Feng, 楊事峯
• Other Authors: 石豫臺
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/37766639662377254202

碩士 === 國立彰化師範大學 === 物理學系 === 97 === This thesis is devoted to the characterization of Eu-doped ZnO thin films deposited on sapphire substrates by pulsed–laser deposition method. The deposited thin films were treated with laser pulse irradiation and thermal annealing..The composition, structure, electrical and optical properties of the thin films were investigated. Eu concentration of the ZnO:Eu thin films was determined by energy dispersive spectroscopy. X-ray diffraction results showed the (002) peak from ZnO:Eu thin films shifts to lower angles as the laser irradiation time increases or the irradiation energy decreases. For the thin films irradiated by laser pulse of 250mJ, a hexagonal structure of ZnO crystal was found by the atomic force microscope measurements. From the Hall effect measurements, a laser-irradiation-induced conversion of these semiconductor thin films from n-type to p-type was confirmed. The thin films showed good transparency. The optical transmittance in visible range is over 70%. The photoluminescence (PL) spectra of ZnO:Eu thin films excited by laser beam of 325 nm showed red emission bands, which was due to the transition of inner energy levels of Eu3+ ions.. The temperature-dependent PL spectra of ZnO:Eu thin films showed that the red emission intensity decreases with the temperature increases.