Estudo da fotoluminescência do Ga2O3 contendo a impureza Cr3+

Abstract

In this work a study of the photoluminescence of β-Ga2O3 as a function of Cr3+ impurity concentration was carried out. The samples were synthesized by solid state reaction with 0.1%, 1% and 5% of Cr3+. The optical properties were investigated by photoluminescence and excitation photoluminescence techniques at room temperature and atmospheric pressure. In the emission spectra were identified the R lines, which are characteristic of the 2E(2G) → 4A2(4F) transition of Cr3+ in octahedral site, superimposed on a broad and intense band in the near infrared region characteristic of the 4T2 (4F) → 4A2(4F) transition of Cr3+ in octahedral site. In photoluminescence excitation measurements the transitions 4A2( 4F) → 4T1(4F) and 4A2(4F) → 4T2(4F) were identified which are two bands in the visible region of the electromagnetic spectrum. The excitation and photoluminescence spectra were analyzed and interpreted according to the Crystal Field Theory and by the Tanabe-Sugano diagram for ion with d3 electronic configuration, and the crystal field parameters Dq and B were calculated from the solutions of the Tanabe-Sugano matrices. The decay time for the sample containing 0.1% Cr3+ was 0.22 ms and for the sample containing 1% Cr3+ was 0.11 ms, characteristics of the Cr3+ in octahedral sites.