Erbium upconversion luminescence from sol-gel derived multilayer porous inorganic perovskite film

Erbium-doped barium titanate (BaTiO3:Er) xerogel film with a thickness of about 500 nm was formed on the porous strontium titanate (SrTiO3) xerogel film on Si substrate after annealing at 800 °C or 900 °C. The elaborated structures show room temperature upconversion luminescence under 980 nm excitation with the photoluminescence (PL) bands at 523, 546, 658, 800 and 830 nm corresponding to 2H11/2→4I15/2, 4S3/2→4I15/2, 4F9/2→4I15/2 and 4I9/2→4I15/2 transitions of trivalent erbium. Raman and X-ray diffraction (XRD) analysis of BaTiO3:Er\porous SrTiO3\Si structure showed the presence of perovskite phases. Its excellent up-conversion optical performance will greatly broaden its applications in perovskite solar cells and high-end anti-counterfeiting technologies

Optical Properties and Upconversion Luminescence of BaTiO3 Xerogel Structures Doped with Erbium and Ytterbium

Erbium upconversion (UC) photoluminescence (PL) from sol-gel derived barium titanate (BaTiO3:Er) xerogel structures fabricated on silicon, glass or fused silica substrates has been studied. The fabricated structures under continuous-wave excitation at 980 nm and nanosecond laser excitation at 980 and 1540 nm demonstrate room temperature PL with the bands at 410, 523, 546, 658, 800 and 830 nm, which correspond to the 2H9/2 → 4I15/2, 2H11/2 → 4I15/2, 4S3/2 → 4I15/2, 4F9/2→ 4I15/2 and 4I9/2→ 4I15/2 transitions in Er3+ ions. The intensity of erbium UС PL increases when an additional macroporous layer of strontium titanate is used beneath the BaTiO3 xerogel layer. It is enhanced for BaTiO3 xerogel films codoped with erbium and ytterbium (BaTiO3:Er,Yb). The redistribution of the intensity of the PL bands is observed for the latter and it depends on the excitation conditions. Finally, a Bragg reflector and a microcavity structure comprising of alternating (BaTiO3:Er,Yb) and SiO2 xerogel layers were fabricated with the cavity mode near the red PL band of Er3+ ions. Enhancement of UC PL from the microcavity was observed for the sample annealed from 450°C to 600°C. The fabricated cavity structures annealed at 450°C allow us to tune the cavity mode with 10 nm shift within the temperature range from +20°C to +130°C. Photonic application of BaTiO3 xerogel structures doped with lanthanides is discussed

Ап-конверсионная люминесценция в ксерогеле титаната бария, легированном эрбием и иттербием, в пористом анодном оксиде алюминия

In this work, sol-gel synthesis and luminescence properties of erbium and ytterbium doped BaTiO3 (BaTiO3:Er,Yb) in porous anodic alumina are reported. Porous anodic alumina with its well-known tailor-made honeycomb structure was chosen as a template for the sol-gel synthesis of BaTiO3:Er,Yb. Porous anodic alumina was fabricated either on silicon wafer or aluminum foil. The sol corresponding to xerogel content of Ba0,76Er0,04Yb0,20TiO3 was deposited on porous anodic alumina by spinning, which was followed by drying and heat treatment at a relatively low temperature 450 °C on aluminum foil or 800 °C on silicon. Porous anodic alumina known also as an optically anisotropic structure differed in the experiments by diameter of the pores and thickness. Evidently, all fabricated samples demonstrated a roomtemperature erbium upconversion luminescence under excitation in the continuous-wave (CW) mode with a focused 980 nm laser beam of a 200 mW diode module. Erbium upconversion luminescence is characterized by the bands at 410, 523, 546, and 658 nm, corresponding to the 2H9/2 → 4I15/2, 2H11/2 → 4I15/2, 4S3/2 → 4I15/2 and 4F9/2 → 4I15/2.В статье рассмотрен золь-гель-синтез и люминесцентные свойства титаната бария, легированного эрбием и иттербием (BaTiO3:Er,Yb), в пористом анодном оксиде алюминия. Пористый анодный оксид алюминия с его хорошо известной ячеистой структурой был выбран в качестве матрицы для золь-гель-синтеза BaTiO3:Er,Yb. Пористый анодный оксид алюминия изготавливали на кремниевой пластине и алюминиевой фольге. Раствор, соответствующий составу ксерогеля Ba0,76Er0,04Yb0,20TiO3, осаждался на пористый анодный оксид алюминия методом центрифугирования с последующей сушкой и термообработкой при относительно низкой температуре 450 °C на алюминиевой фольге или при 800 °C на кремнии. Пористый анодный оксид алюминия, известный также как оптически анизотропная структура, в эксперименте отличался размером пор и толщиной. По результатам испытаний установлено, что все изготовленные образцы демонстрируют ап-конверсионную люминесценцию эрбия при комнатной температуре при возбуждении диодным модулем в непрерывном режиме сфокусированным излучением лазерного диода на длине волны 980 нм мощностью 200 мВт. Ап-конверсионная люминесценция эрбия характеризуется полосами с максимумом на длинах волн 410, 523, 546 и 658 нм и соответствующими им переходами 2H9/2 → 4I15/2, 2H11/2 → 4I15/2, 4S3/2 → 4I15/2 и 4F9/2 → 4I15/2

Upconversion Luminescence of Er3+ Ions from Barium Titanate Xerogel Powder and Target Fabricated by Explosive Compaction Method

Photo- and cathodoluminescence in the visible range from erbium-doped barium titanate xerogels obtained in the form of a powder and a target pressed from it by explosive compaction are investigated. The powder and target exhibit upconversion luminescence of erbium ions excited at wavelengths in the regions 950–1000 and 1450–1550 nm that is characterized by strong bands at 650 and 520–560 nm and a weak band at ~820 nm that correspond to the 4F9/2 → 4I15/2, 2H11/2 → 4I15/2, 4S3/2 → 4I15/2, and 4I9/2 → 4I15/2 transitions of Er3+. The target also demonstrates cathodoluminescence at room temperature and liquid nitrogen temperature with the strongest bands at 650, 520, and 538 nm