Energy transfers in telecommunication-band region of (Sc,Er)2O3 thin films grown on Si(111)

Abstract

The energy transfer dynamics in 1.5-μm region of (ErxSc1-x)2O3 epitaxial thin films grown on Si(111) were investigated via temperature-dependence of the time-resolved photoluminescence (TR-PL). In order to exclude the dissipation via the cooperative up- conversion, the low power and resonant excitation of the third crystal-field level (4I13/2 : Y'3) of the Er3+ site with C3i symmetry was employed. The TR-PL measurements of the Y'1- Z'1 transition have proved the existence of two decay components having fast (10-100 μs) and slow (0.1-1 ms) relaxation times in the range of 4-60 K. The model calculation including the temperature-sensitive and -insensitive non-radiative relaxations could explain well all the observed results. Moreover, the long averaged inter-Er-ion distance by decreasing Er density was found to be very effective to reduce both non-radiative relaxation rates.