Analysis of X-ray diffraction patterns of blue ACTFEL devices for flat panel displays using synchrotron radiation

Abstract

X-ray diffraction from synchrotron radiation is used to characterize the entire stack of layers that form a blue AC thin-film electroluminescence (ACTFEL) display device for flat panels. This technique allows characterization of all the individual layers within the context of the fabricated device, providing greater insight into device structure and performance. A designed experiment with eight samples was performed in order to investigate what factors and factor values can improve the blue-light emission of these ACTFEL display devices. It was found that the factor that correlated best with device performance was the uncontrolled concentration in the final device of strontium oxide from the strontium sulfide source material. No other variable correlated as well. This result shows the power of the synchrotron radiation x-ray diffraction technique as a characterization tool for ACTFEL display devices, and it shows that SrSO4 may be limiting device performance of blue display devices.