Electron spin resonance and luminescence in Ga2−xEuxS3 single crystals Original Research Article

In present work electron spin resonance (ESR) and luminescence have been studied in Ga2−xEuxS3 single crystals. The ESR and photoluminescence (PL) spectra of Ga2−xEuxS3 were observed and the intensity of these spectra has increased linearly with the Eu concentrations in the samples. At the low temperature of 3.8 K in Ga2−xEuxS3 single crystals, when the magnetic field has been applied as the perpendicular to the direction of [110], the hyperfine structure of ESR spectra has been observed. The exchange interaction of Eu2+ atoms in Ga2−xEuxS3 single crystals have been determined as, g=4.2. The PL spectrum of pure Ga2S3 single crystals was recorded at 4.2 K and consisted of a narrow high-energy band at 2.53–2.38 eV and a low-energy band at 2.14–1.59 eV. Ga2−xEuxS3 resulted in complete quenching of the impurity luminescence bands gave rise to a green europium band (2.38–2.14 eV) in the luminescence spectrum. Crystals of Ga2−xEuxS3 emitted bright green electroluminescence (EL) spectrum when they excited with static and alternating electric fields at 77 K. We have also determined the field and frequency dependences of the EL.