{'fraction_non_alphanumeric': 0.042379788101059496, 'fraction_numerical': 0.04726976365118175, 'mean_word_length': 4.658986175115207, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 1, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Photoluminescent Properties of Eu3+ in Ga2O3:Cr3+ Films Prepared by Metal Organic Deposition

We demonstrate the synthesis of β-Ga2O3:Eu3+ red-emitting films by metal–organic deposition and report the photoluminescence (PL) properties of such films measured from 20 to 450 K. β-Ga2O3 is one of five well-known modifications of gallium oxide. The X-ray diffraction analysis indicates that only β-phase Ga2O3 can be synthesized by calcination at Tc≥800 °C. An activation energy of ∼0.65 eV for the Eu3+ ions in β-Ga2O3 is determined from a plot of Eu3+-related red emission intensity vs calcination temperature. Lattice temperature dependences of the PL spectrum and luminescence decay time were performed at T = 20–450 and 20–300 K, respectively. No strong temperature dependences of the red emission intensity and decay time were observed below 300 K; however, the PL intensity at T > 300 K exhibited a gradual decrease with increasing T, yielding a quenching energy of ∼0.5 eV. The films calcined at Tc≥900 °C revealed a deep-red emission band peaking at ∼1.7 eV, together with two sharp red emission peaks at ∼1.78 and ∼1.80 eV. These emission band and peaks were attributed to the Cr3+ ions unintentionally doped in β-Ga2O3.