Application of <I>β</I>-NaYF<SUB>4</SUB>:Er<SUP>3+</SUP> (2%), Yb<SUP>3+</SUP> (18%) Up-Conversion Nanoparticles in Polymer Solar Cells and its Working MechanismMei Yang, Wei Huang, Yingfang Fan et al.|Journal of Nanoscience and Nanotechnology|2016Cited by 5