Room temperature visible green luminescence from a-GaN:Er film deposited by DC magnetron sputtering

Abstract

The GaN:Er thin film has been prepared by direct current (DC) planar magnetron sputtering method. The film was characterized by X-ray diffraction (XRD), Raman, Fourier transform infrared (FTIR) absorption, ultraviolet–visible (UV–vis) and photoluminescence (PL) spectra. XRD and Raman spectrum show the structure of the film is amorphous. FTIR result indicates that the main absorbance of the film is Ga–N stretching vibration. From UV–vis result the optical band gap of the film has been calculated as 3.74 eV. Green PL spectrum due to intra-4f transitions of Er 3+ has been observed at room temperature: 2H 9/2– 4I 15/2(430 nm), 2H 11/2– 4I 15/2(520 nm), 4S 3/2– 4I 15/2(580 nm).