open access

https://hdl.handle.net/2115/74809

Red-emission over a wide range of wavelengths at various temperatures from tetragonal BaCN2:Eu2+

英語

2018-06-28

Royal Society of Chemistry

Journal of materials chemistry C

6(24)

6370-6377

A new polymorph of BaCN2 was obtained via a simple nitridation reaction of BaCO3 under an NH3 flow at 900 1C. The product was analyzed via single crystal X-ray diffraction and infrared spectroscopy, and it was found to have a tetragonal I4/mcm crystal structure (space group no. 140) with a = 0.60249(4) nm and c = 0.71924(5) nm. In this structure, each Ba2+ cation is situated in the square antiprism of N atoms of NCN(2-)anionic groups. Eu2+ doped BaCN2 can be excited by irradiation of blue and green light (from 400 to 550 nm), and it generates an intense red emission peak at 660 nm with a quantum efficiency of 42% in response to 465 nm excitation at room temperature. The peak emission wavelength varies over an extremely wide range of temperature, from 640 nm at 500 K to 680 nm at 80 K, and this red-shift with decreasing temperature is attributed to a unit cell shrinkage that results in significant crystal field splitting of the 5d energy levels of the Eu2+ ions.

学術雑誌論文

Accepted Manuscript

2050-7526