Intense Red Catho- and Photoluminescence from 200 nm Thick Samarium Doped Amorphous AlN Thin Films

Muhammad Maqbool,Tariq Ali

doi:10.1007/s11671-009-9309-7

Abstract

Samarium (Sm) doped aluminum nitride (AlN) thin films are deposited on silicon (100) substrates at 77 K by rf magnetron sputtering method. Thick films of 200 nm are grown at 100–200 watts RF power and 5–8 m Torr nitrogen, using a metal target of Al with Sm. X-ray diffraction results show that films are amorphous. Cathodoluminescence (CL) studies are performed and four peaks are observed in Sm at 564, 600, 648, and 707 nm as a result of4G5/2 → 6H5/2,4G5/2 → 6H7/2,4G5/2 → 6H9/2, and4G5/2 → 6H11/2transitions. Photoluminescence (PL) provides dominant peaks at 600 and 707 nm while CL gives the intense peaks at 600 nm and 648 nm, respectively. Films are thermally activated at 1,200 K for half an hour in a nitrogen atmosphere. Thermal activation enhances the intensity of luminescence.

Highlights

Rear-earth doped nitride semiconductors thin films are attracting increasing attention as phosphor materials, and are used for optical displays [1,2,3,4,5]
Recent progress toward nitride-based light-emitting diode and electroluminescent devices (ELDs) has been made using crystalline and amorphous aluminum nitride (AlN) doped with a variety of rare-earth elements [1,2,3,4,5,6,7,8,9]
Because of the combination of these colors and dominancy of orange-red peak, the direct observation of AlN:Sm films exposed to electron beam in CL gives orange-red light to naked eye

Summary

Introduction

Rear-earth doped nitride semiconductors thin films are attracting increasing attention as phosphor materials, and are used for optical displays [1,2,3,4,5]. Sputter deposited AlN has been shown to be a viable host for luminescent rare earth (RE) ions due to its transparency over a wide range, M. When these materials are excited by various means, intense sharp-line emission is observed due to intra-4fn-shells transitions of the rare-earth ion core [18,19,20,21]. No diffraction peaks were observed, indicating that the as-deposited films were amorphous.

Results

Conclusion