عنوان مقاله [English]
Recently, upconversion nanoparticles have attracted tremendous attention and have been employed for verity of applications. Here, we investigate the impact of applying different temperatures on the optical function of NaYF4:Yb3 , Er3 upconversion nanoparticles. Therefore, upconversion nanoparticles are doped in a polymer matrix and excited with a 980 nm laser beam. Its fluorescence spectrum comprises of 4 peaks in the red, green and blue bands and appeared in green color. Then, the temperature was slowly increased from 25C° up to 75C°and subsequently decreases to investigate the fluorescence intensity at two wavelength peaks of 525 nm and 541 nm. Results indicates that the fluorescence intensity decreases by increasing the temperature, due to non-radiative decays induces by thermal de-excitation in the NaYF4 host matrix, and increase again by reducing the temperature.