AVS 46th International Symposium
    Flat Panel Displays Topical Conference Monday Sessions
       Session FP-MoA

Paper FP-MoA9
A Comparison of the Short Wavelength Performance of ZnS and SrS Thin-Film Electroluminescent Devices via a Rare Earth Doping Study

Monday, October 25, 1999, 4:40 pm, Room 604

Session: Luminescent Thin Films
Presenter: C.M. Maddix, Oregon State University
Authors: P.D. Keir, Oregon State University
C.M. Maddix, Oregon State University
B. Baukol, Oregon State University
J.F. Wager, Oregon State University
B.L. Clark, Oregon State University
D.A. Keszler, Oregon State University
Correspondent: Click to Email
The short wavelength electroluminescent (EL) performance of SrS and ZnS phosphors for thin-film EL flat-panel display applications is compared. This is accomplished by measuring the EL spectra of ZnS and SrS EL devices doped with various rare earth luminescent impurities: Dy, Er, Ho, Tb, and Tm. All of the SrS EL devices tested have more intense EL emission at short wavelengths than corresponding ZnS EL devices. Additionally, all of the SrS EL devices operate at smaller average phosphor fields. The superior EL performance of SrS appears to be due to a hotter electron distribution and to the presence of positive space charge in SrS EL devices. The ZnS devices show a distinct EL cut-off at ~440-460 nm. This is attributed to an inadequately heated electron distribution which is unable to excite high energy transitions in the luminescent impurity. Collectively, these results indicate that efficient blue emission from a ZnS phosphor is unlikely.