Luminescence from Al2xGa2(1−x)O3:Cr3+

Abstract

Detailed luminescence and lifetime data are presented for the mixed crystal system Al_2xGa_2(1−x)O₃:Cr³⁺, where x=0, 0.02, 0.20, 0.35, 0.98, 1.0. The experimental data, obtained under broadband excitation at 77 K and 4 K, indicate that our pressure‐grown microcrystalline samples all have the corundum (α‐Al₂O₃) structure. The main features of the luminescence are explained in terms of the shifts, due to strain, of the chromium ion energy levels. Some experimental evidence for energy transfer among the optical centers is also presented.