Oxygen vacancy-assistant enhancement of photoluminescence performance of Eu3+ and La3+-codoped BiOCl ultrathin nanosheets

摘要： The Eu3+ and La3+ co-doped BiOCl ultrathin nanosheets were prepared through a facile solvothermal method. The samples were characterized using different techniques to study the structure, morphology, and luminescence. The solvothermal derived samples exhibit the morphology of ultrathin nanosheet. The photoluminescence spectrum of the Eu3+ ions doped BiOCl sample shows a broad emission band in the wavelength range of 380–480 nm due to the oxygen vacancies present in the sample. The spectrum also shows sharp characteristic emission peaks of Eu3+ ions. The intensity of this broad emission band increases with the incorporation of La3+ ions, due to the increase in oxygen vacancies. These results were demonstrated by the XPS spectra for all the samples. It was found that the overall luminescence intensity for the BiOCl: Eu3+, La3+ ultrathin nanosheet was about 300% stronger than the BiOCl: Eu3+ ultrathin nanosheet. As the La3+ ions concentration increases the CIE values shift from bluish-white region to white.