The upconversion mechanism based on lanthanide ions has been studied in several systems and has been applied in various fields, such as sensors, biological markers, and photovoltaic cells. This work investigates the properties of the lanthanides Er³⁺ and Yb³⁺ doped into titanium oxide at different molar concentrations. The sol–gel methodology and the spin-coating technique were used to prepare the thin films. To promote the upward energy conversion mechanism, the materials were submitted to thermal treatment at 500 °C after the depositions. Before and after thermal treatment, the films presented 80% and 83% optical transparency above 350 nm, respectively. The X-ray diffractograms of all the films attested to the beginning of TiO₂ crystallization, as evidenced by the characteristic peak of the titania phase (JCPDS # 23-1446). The emission spectra of the films excited at 980 nm exhibited the characteristic Er³⁺ emission bands in the green (525 and 555 nm) and red (660 nm) regions, which corresponded to the ⁴H_11/2/⁴S_3/2 → ⁴I_15/2 and ⁴F_9/2 → ⁴I_15/2 transitions, respectively. On the basis of the emission intensity as a function of laser power, two photons were involved in the process. The Fluorescence Intensity Ratio (FIR) indicated a rise in the local temperature, which was induced by excitation light, or the laser power.

基于镧系元素离子的上转换机理已经在几种系统中进行了研究，并已应用于各种领域，例如传感器，生物标记和光伏电池。这项工作研究了掺杂在不同摩尔浓度的氧化钛中的镧系元素Er ³⁺和Yb ³⁺的性能。溶胶-凝胶法和旋涂技术用于制备薄膜。为了促进向上的能量转换机制，在沉积后将材料在500°C下进行热处理。热处理前后，薄膜在350 nm以上的光学透明度分别为80％和83％。所有薄膜的X射线衍射图证明了TiO ₂的开始由二氧化钛相的特征峰证实（JCPDS＃23-1446）。在980 nm激发的薄膜的发射光谱在绿色（525和555 nm）和红色（660 nm）区域显示出特征性的Er ³⁺发射带，对应于⁴ H _11/2 / ⁴ S _3/2  →  ⁴我_15/2和⁴ ˚F _9/2  →  ⁴我_15/2过渡，分别。根据发射强度与激光功率的关系，该过程涉及两个光子。荧光强度比（FIR）表示局部温度升高，这是由激发光或激光功率引起的。