Rare earth ions (Er, Ho and Sm) regulate the optical and photoluminescence properties of CaAl12O19: Performance prediction and anti-counterfeiting application
Articles
Electronic International Standard Serial Number (EISSN)
1873-3956
abstract
Er3+, Ho3+ or Sm3+ single-doped hexaluminate CaAl12O19 phosphors were successfully synthesized by a simple polyacrylamide gel method. Low concentration of Er3+, Ho3+ or Sm3+ ions doped CaAl12O19 changed the lattice parameters of CaAl12O19 but did not change its phase structure. A variety of characterization techniques confirmed that the Er3+, Ho3+ or Sm3+ ions occupied part of the position of Ca2+ ions and transformed the surface morphology from the lamellar CaAl12O19 to nanoparticles. The color, optical properties and photoluminescence properties of CaAl12O19: Er, Ho, Sm phosphors are affected by different rare earth ions and their contents. Er3+, Ho3+ or Sm3+ ions introduces CaAl12O19 which changes its color to bright white and decreases the Eg value. The nonlinear dependence between the reflectance of CaAl12O19: Er, Ho, Sm phosphors and the content of rare earth ions makes the back propagation neural network model play a great advantage in predicting their color properties. The CaAl12O19: Er, CaAl12O19: Ho, and CaAl12O19: Sm phosphors exhibits obvious emission peaks at 472, 533 and 418 nm with the excitation wavelengths of 310, 370 and 251 nm, respectively. Compared with the literature, CaAl12O19: Er, CaAl12O19: Ho, and CaAl12O19: Sm phosphors show novel luminescence phenomena and are strongly dependent on synthesis methods. The fluorescence emission intensity of CaAl12O19: Er, CaAl12O19: Ho, and CaAl12O19: Sm phosphors increased with the increasing of Er3+, Ho3+ or Sm3+ ion content. Anti-counterfeiting applications show that the CaAl12O19: Er, CaAl12O19: Ho, and CaAl12O19: Sm phosphors have potential applications in the fields of sky blue, green and dark blue luminescence, respectively.
Classification
keywords
anti-counterfeiting; caal12o19; emission peak; neural network model; polyacrylamide gel method