Open AccessSynthesis， electronic structure and optical properties of MBiO2Cl (M=Ca，Sr，Ba)
Author(s) -
HuiLiang Li,
Junhua Yuan,
Xiaojun Wang,
JingTai Zhao,
Zhijun Zhang,
Xinxin Yang
Publication year - 2008
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.57.7878
Subject(s) - luminescence , materials science , bismuth , scintillator , ultraviolet , excited state , ion , band gap , radius , absorption (acoustics) , semiconductor , absorption spectroscopy , atomic physics , analytical chemistry (journal) , optics , optoelectronics , physics , chemistry , chromatography , metallurgy , computer security , quantum mechanics , detector , computer science , composite material
The absorption electronic structure and luminescence spectrum of three Sillen bismuth oxyhalides CaBiO2Cl SrBiO2Cl and BaBiO2Cl are reported and analyzed. The calculated electronic structure by the density functional theory shows that both SrBiO2Cl and BaBiO2Cl are semiconductors with direct band gap which are consistent with the results of ultraviolet (UV)-vis diffuse reflectance experiment. The X-ray and UV excited luminescent spectra show a broad emission band extending from 400 to 550nm at room temperature. The light yield of BaBiO2Cl powders is about 1.4 times that of Bi4Ge3O12 (BGO) powders at room temperature under X-ray excitation and BaBiO2Cl powders have shorter decay times of 100ns (22%) 300ns (41%) and 600ns (37%) compared with those of the BGO powders. The luminescence properties show a correlation between Bi—O(Cl) distance and radius of M2+ ions. Considering that the density of BaBiO2Cl is 6.98g/cm3 it may be a potential practical scintillator.