p-ZnxMg1-xO：Na/n-ZnO p-n junction light emitting diode （LED） was produced on n-ZnO （0001） single-crystal substrate using pulsed laser deposition. The realization of band gap engineering was achieved by the incor-poration of Mg in ZnO layers and was confirmed by photoluminescence spectrum. The p-type ZnxMg1-xO：Na film with low resistance was obtained at 500 ℃ and in which, Na has taken effect evidenced by Hall and X-ray photo-electron spectroscopy measurements. The current-voltage curve of LED showed a rectifying behavior and obvious electroluminescence was realized by feeding a direct current up to 40 mA. Furthermore, its structural and electric characters are discussed as well.
Er doped ZnO thin films were grown on Si substrates using SiO2 buffer layer by pulsed laser deposition (PLD) method. The obtained films crystallize well and show high c-axis orientation. The Er content was evidently detected by the energy dispersive X-ray spectroscopy (EDS). Upon annealing in O2 ambience at different temperatures, the films show different photoluminescence properties at 1.54 μm. The samples annealed at 700 and 850 ℃ show intense photoluminescence peaks which enhance with the annealing temperature, while no obvious luminescence peaks are observed for the as-grown samples or annealed at 500 ℃. The possible mechanism was discussed.
GU Xiuquan ZHU Liping YE Zhizhen HE Haiping ZHAO Binghui
