| Local Structure about Cu in CuS Nano-precipitates within ZnS |
| Abstract ID | MAT-03 |
| Presenter | Yu
Jiang |
| Presentation Type | Poster
|
| Full Author List | Y. Jiang (1) , J. Stanley (1) , F. Bridges (1)
|
| Affiliations | (1) University of California, Santa Cruz CA 95060
|
| Category | Materials Science |
| Abstract | Recently it has been discovered that after an AC electroluminescence (EL) device, made from of ZnS:Cu,Cl, has significantly degraded under AC operation, it can be significantly rejuvenated with a low temperature anneal at 180-200°C. However annealing at a slightly higher temperature - 240°C strongly degrades the electroluminescence. Since the AC electroluminescence depends critically on the
presence of tiny CuS precipitates, one possibility is that the CuS precipitates are changing. Here we present Cu K-edge EXAFS data on ZnS with 0.15% Cu and compare with corresponding data for CuS. The data for ZnS (0.15% Cu) were
extended to 550K (277°C) to cover the temperature at which thermal degradation occurs. The results show no significant change in the broadening of the Cu-S pair distribution function as a function of T and no significant change in the absorption edge. The \sigma2(T) data for ZnS (0.015% Cu) can be well fit to a correlated Debye model with a Debye temperature close to that for bulk CuS. Thus the degradation of the AC electroluminescence must result from some other local changes.
|
| Footnotes | |
| Funding Acknowledgement | Work supported by DOE grant DE-FG02-07ER46388. |
