PHOSPHOR THIN FILM, PREPARATION METHOD, AND EL PANEL

The invention aims to provide a phosphor thin film eliminating a need for filters, having a satisfactory color purity and useful as the blue color in full-color EL displays, a method for preparing the same and an EL panel. Such objects are achieved by a phosphor thin film formed of a matrix material comprising barium thioaluminate as a main component to which magnesium is added and rare earth element, Eu is added as a luminescent center, a method for preparing the same, and an EL panel using the same.