Erbium location into AlN films as probed by spatial resolution experimental techniques

TL;DR

This study uses advanced microscopy and diffraction techniques to precisely locate erbium atoms within AlN films, revealing their substitutional sites and implications for photoluminescence behavior.

Contribution

It provides detailed experimental evidence on erbium localization in AlN films, showing they form a solid solution without phase separation and primarily occupy metal sites.

Findings

Erbium forms a solid solution up to 6 at.% without precipitating.

Erbium predominantly substitutes metal sites in the AlN w{"u}rtzite structure.

Insights into photoluminescence quenching mechanisms based on erbium concentration.

Abstract

This paper presents a thorough experimental investigation of erbium-doped aluminium nitride thin films prepared by R.F. magnetronsputtering, coupling Scanning Transmission Electron Microscopy X-ray-mapping imagery, conventional Transmission Electron Microscopy and X-ray diffraction. The study is an attempt of precise localisation of the rare earth atoms inside the films and in the hexagonal w{\"u}rtzite unit cell.The study shows that AlN:Erx is a solid solution even when x reaches 6 at.%, and does not lead to the precipitation of erbium rich phases. The X-ray diffraction measurements completed by simulation show that the main location of erbium in the AlN w{\"u}rtzite is the metal substitution site on the whole range. They also show that octahedral and tetrahedral sites of the w{\"u}rtzite do welcome Er ions over the [1.6--6%] range. The XRD deductions allow some interpretations on the theoretical mechanisms of the photoluminescence mechanisms and more specifically on their concentration quenching.