Visible emission from amorphous AlN thin-film phosphors with Cu, Mn, or Cr

Abstract

Luminescence studies of amorphous AlN incorporated with pure Cu, Mn, or Cr and codeposited with (Cu, Tb, Mn) were performed at 300 K. Thin films of Cu, Mn, and Cr amorphous AlN, ∼200 nm thick, were grown on p-Si(111) substrates using rf magnetron sputtering in a nitrogen atmosphere. Cathodoluminescence showed that pure Cu incorporated amorphous AlN films have strong emission in the blue (∼420 nm) and Mn and Cr incorporated films luminescence in the red (∼690 nm). Cr3+ emission is likely more intense than Mn4+ because chromium does not suffer from incomplete charge compensation in the III–V semiconductor. Luminescence studies of layered structures where pure Cu incorporated films are grown on top of pure Cr incorporated films reveal emission from both Cr and Cu ions. The migration of Cr ions during the 1000 °C luminescence activation step is confirmed with secondary ion mass spectrometry depth profiling. Co-deposited films of Cu, Tb, and Mn show Cu emission around 530 nm instead of 420 nm due to coactivation by Mn.