Manufacture and characterization of novel ACTFEL materials and devices

The aim of this dissertation is to develop non-traditional approaches to alter-nating-current thin-film electroluminescent (ACTFEL) device fabrication. ACTFEL technology suffers from a lack of adequately bright and efficient primary-color phosphors and cannot presently compete in the low-cost display market. Therefore the research presented in this dissertation focuses on an exploration of promising but relatively uninvestigated phosphor materials and low-temperature processing techniques. ACTFEL devices with Zn₂GeO₄:Mn phosphor layers are fabricated and produce excellent luminance and good green chromaticity. Due to the novelty of oxide ACTFEL phosphor materials, the electro-optic behavior of Zn₂GeO₄:Mn ACTFEL devices is thoroughly characterized. ACTFEL devices with MgS:Eu devices are investigated and shown to produce very bright orange light emission and semi-ideal electrical behavior. By doping MgS with various trivalent lanthanide ions, the ability of MgS ACTFEL devices to support blue light emission is verified and the electron energy distribution is evaluated in comparison to the well-known ACTFEL phosphor materials ZnS and SrS. In addition to new materials investigation, a novel low-temperature processing technique is developed. Hydrothermal annealing is shown to recrystallize sputtered Zn₂GeO₄:Mn thin-films, resulting in excellent green photoluminescent emission from an inorganic material processed at temperatures as low as 125°C. This low-temperature technique is used to fabricate operational inorganic ACTFEL devices on flexible plastic substrates.