Вплив умов одержання і збудження на спектральні і кінетичні характеристики катодолюмінесценції тонких плівок Y2O3:Eu

The spectra and kinetics of the rise and decay of the cathodoluminescence (CL) of thin films of Y2O3:Eu obtained by RF-magnetron sputtering were investigated. Based on the shape of the CL spectra at different excitation energies, it showed the possibility of creating irregular solutions of yttrium and europium oxides and the structural features of the surface and bulk layers. The time constant for the decay CL for 612 nm emission was determined and the value of which is within the range (1.8 - 4.1) ms. This value is a complex function of the type of film deposition atmosphere, the activator concentration, and the duration of the exciting pulses was shown. The features of the risen CL and the proposal based on the delayed rise CL analyze structural perfection of Y2O3:Eu  thin films.Досліджено спектри та кінетику розгоряння і загасання катодолюмінесценції (КЛ) тонких плівок Y2O3:Eu отриманих методом ВЧ-магнетронного напилення. На основі форми спектрів КЛ при різних енергіях збудження показано можливість утворення нерегулярних розчинів оксиду ітрію і європію та особливості структури поверхневих і об’ємних шарів. Визначено постійну часу загасання КЛ для свічення 612 нм, величина якої перебуває в межах (1,8 - 4,1) мс. Показано, що дана величина є складною функцією від виду атмосфери напилення плівок, концентрації активатора і тривалості збуджуючих імпульсів. Досліджено особливості розгоряння КЛ і запропоновано на основі затримки розгоряння КЛ аналізувати структурну досконалість тонких плівок Y2O3:Eu

Luminescence Centers in Thin Films of ZnGa2O4

Photoexcitation spectra and luminescence of thin films of ZnGa2O4 under photo-, cathode and X-ray excitation were investigated. Luminescence spectra were factorized on ultimate constituents using Alentsev-Fock method. Emission bands with maximums at 3.35, 2.85, 2.50 and 2.38 eV were referred to the luminescence at the expense of electronic transitions between 4Т2, 4Т1, 2Е and 4А2 terms in octahedral complexes (GaO6)9–. It was proposed an energy level diagram with corresponding electronic transitions in such structure. Luminescence band with maximum at 1.75 eV is attributed to oxygen vacancies. Keywords: zinc gallate, thin films, luminescence, spectrum, energy levels.</span

Edge Absorption of (Y_0.06Ga_0.94)₂O₃ Thin Films

Fundamental absorption edge of (Y0.06Ga0.94)2O3 thin films, obtained by radio-frequency ion-plasmous sputtering, was investigated using the method of optical spectroscopy. It was established that these films are formed in the monoclinic structure of β-Ga2O3. The optical band gap of these films is greater than β-Ga2O3 films and is 4.66 eB for films annealed in oxygen atmosphere, 4.77 eV for the films annealed in argon atmosphere and 4.87 eV for the films, restored in a hydrogen atmosphere. Consolidated effective mass of free charge carriers in (Y0.06Ga0.94)2O3 films after annealing and after reconstitution in hydrogen was estimated. It was found that the concentration of charge carriers after annealing in oxygen atmosphere is 1.32×1018 cm-3, after annealing in argon atmosphere - 3.41×1018 cm-3 and after reconstitution in hydrogen is 5.20×1018 cm-3, which is typical for degenerated semiconductors. It was shown that the shift of fundamental absorption edge in (Y0.06Ga0.94)2O3 thin films is caused by Burstein-Moss effect. Key words: gallium and yttrium oxide, thin films, fundamental absorption edge.</span