Luminescence from thulium and samarium doped amorphous AlN thin films deposited by RF magnetron sputtering and the effect of thermal activation on luminescence

Department of Science and Mathematics, Mount Olive College, 634 Henderson Street, Mount Olive, NC 28365, USA

Corresponding author: mmaqbool@moc.edu

Received: 26 August 2005
Revised: 9 November 2005
Accepted: 9 November 2005
Published online: 23 March 2006

Abstract

Thin films of thulium and samarium doped AlN are deposited on silicon (111) substrates at 77 K by rf magnetron sputtering method. 200–400 nm thick films are grown at 100–200 watts RF power and 5–8 mtorr nitrogen, using a metal target of Al with Tm and Sm separately. X-rays diffraction results show that films are amorphous. Cathodoluminescence studies are performed at room temperature and two dominant peaks are observed in Tm at 467 nm from transition and 480 nm from ¹G₄ to the ground state ³H₆ transition. Other peaks in the visible region are obtained at 650 nm and 685 nm due to and transitions. Peaks in the ultraviolet and infrared region are also obtained at 371 nm, and 802 nm as a result from and transition respectively. Sm gives four peaks at 564 nm, 600 nm, 648 nm and 707 nm as a result of , , and transitions. Films are thermally activated at 1200 K for half an hour in a nitrogen atmosphere. Thermal activation enhances the intensity of luminescence.