Abstract: The nanoparticle rare earth (La、Nd、Sm)  BaO composite thin films were deposited through vacuum evaporation.The shape and size of the nanoparticles of the rare earth affect the photoemission photospectral response threshold of the thin films.The threshold wavelength of the photospectral response of the thin film,in which the rare earth (Sm) nanoparticle shape was sphere,was 720 nm.The threshold wavelengths of the photospectral response of the thin films,in which the rare earth (La and Nd) nanoparticles shape was long,were 650 nm and 660 nm,respectively.We obtained that the equivalent barrier around rare earth nanoparticle was 1.7～2.0 eV.Because the work functions of rare earth nanoparticles and BaO composite are different,the spatial electron distribution around the rare earth nanoparticles is changed in the composite thin films.Then the energy bands around the rare earth nanoparticles become curved.

Key words: Photoemission, Photospectral response, Energy band structure, Rare earth element, Nanoparticle