PREPARATION AND ANALYSIS OF THIN-FILM ELECTROLUMINESCENT DEVICES - PREFACE

Alternating current thin film electroluminescent (ACTFEL) displays are manufactured by thin film technology. The development of these device s has followed the advances made in the deposition and analysis of the phosphor, insulator, and conducting layers. In this work Atomic Layer Deposition (ALD) has been applied in the deposition of phosphor and d ielectric films (including fluorides and composite insulators) and new means for their characterization are devised. In addition, the mechan ism of the ALD method in general is discussed. Progress in understandi ng ACTFEL devices has been achieved by physical electrical, and optica l modeling. In this thesis these topics are taken further and the deve lopment of a simple scheme to combine the theories into a complete mod el for the picture element is attempted. This approach provides tools for the preparation of new optimized structures in the area of multico lor displays in particular. Instrumental in this progress is the appli cation of powerful analysis methods that give information about the st ructure and processes in the thin film stack. In this work the traditi onal measurements of electrical and optical properties have been exten ded by fitting the measured continuous data to theoretical models. Thi s allows the evaluation of a number of internal parameters which previ ously were only indirectly obtained. A method is devised for condensin g information about the highly nonlinear breakdown in the phosphor lay er into a few characteristic parameters. For fast film thickness deter mination in multilayer stacks, optical spectroscopy is a unique method . These measurements are used to deduce the visual and electrical prop erties of an ACTFEL display.