LOCAL-STRUCTURE STUDY OF DILUTE ER IN III-V SEMICONDUCTORS BY FLUORESCENCE EXAFS

For understanding the luminescence of Er atoms in III-V semiconductors , OMVPE-grown InP doped with Er has been investigated by fluorescence EXAFS (extended X-ray absorption fine structure) in order to study the local structure around Er atoms. The local structures around the Er a toms doped in InP, with doping as dilute as 3 x 10(12) Er atoms in a 1 .5 mm x 1.0 mm spot, were successfully measured by fluorescence EXAFS. The EXAFS analysis revealed that the Er atoms doped in InP above 853 K (which showed low luminescence) formed the rock-salt-structure ErP, while the Er atoms doped in InP below 823 K (which showed high lumines cence) substituted on the In site of InP. The dependence of the local structure on growth temperature was observed for the samples doped wit h 3 x 10(12) atoms and 1.2 x 10(13) atoms of Er.