STTR PHASE I: Metalorganic Chemical Vapor Deposition Growth on Plasic for Low-Voltage Electroluminescent Displays

*** 9632164 Vernon STTR一期项目将开发塑料基板上的薄膜电致发光显示器。在高温Kapton衬底上，采用金属有机化学气相沉积法（MOCVD）在~425℃下生长没食子酸锌（ZnGa204）荧光粉。发光中心将通过离子注入和脉冲激光对荧光粉进行退火而不损坏衬底来引入。第一阶段将证明氧化物荧光粉可以通过MOCVD沉积在与Kapton相容的温度下，Kapton是一种可使用到450℃的塑料，因为Kapton和其他聚酰亚胺材料的光学不清晰，因此将开发从顶部（非衬底）侧发光的结构。在离子注入发光中心的过程中，衬底温度由水冷却控制。掺杂剂的活化和晶体增强将通过脉冲紫外激光退火来实现，这样就不会降解塑料衬底。佛罗里达大学将使用准分子激光开发适当的紫外退火。玻璃基板将包括作为实验控制。Spire将通过x射线衍射和电子显微镜比较mocvd生长的ZnGa204薄膜在塑料和玻璃基底上的质量，并对退火后的ZnGa2O4薄膜进行光致发光和阴极发光测试。佛罗里达大学随后将在玻璃和塑料基板上制造和测试电致发光装置。第二阶段将包括优化荧光粉生长、发光中心植入和塑料衬底上的激光退火。高介电陶瓷薄膜的低温MOCVD是实现低电压工作和高发光效率的发展方向。Spire的MOCVD氧化物反应器旨在沉积荧光粉和高介电材料，Spire还将尝试通过在同一反应器中快速沉积多层介电-磷-介电堆叠来提高电致发光效率和降低制造成本。这项研究将导致在塑料基板上制造平面EL显示器的能力，用于坚固，明亮，轻便的手持信息终端，为苛刻环境中的人员提供更好的图形通信。＊＊＊

*** 9632164 Vernon This Phase I STTR project will develop thin film electroluminescent displays on plastic substrates. The zinc gallate (ZnGa204) phosphor host will be grown by metalorganic chemical vapor deposition (MOCVD) at ~425 C on a high-temperature Kapton substrate. Luminescent centers will be introduced by ion implantation, and a pulsedlaser anneal of the phosphor without damaging the substrate. Phase I will demonstrate that oxide phosphors can be deposited by MOCVD at temperatures compatible with Kapton, a plastic usable up to ~450 C. Because Kapton, and other polyimide materials, are not optically clear, structures having light emission from the top (nonsubstrate) side will be developed. Substrate temperature will be controlled by water cooling during ion implantation of luminescence centers. Dopant activation and crystal enhancement will be by pulsed ultraviolet (UV) laser annealing, so as not to degrade the plastic substrate. Development of the proper UV anneal, using an excimer laser, will be conducted at the University of Florida. Glass substrates will be included as experimental controls. Spire will compare the quality of MOCVD-grown ZnGa204 films on plastic and glass substrates by x-ray diffraction and electron microscopy, and photoluminescence and cathodoluminescence tests will be performed on annealed ZnGa2O4 films. The University of Florida will then fabricate and test electroluminescent devices on both glass and plastic substrates. Phase II will include optimization of phosphor growth, luminescence-center implantation, and laser annealing on plastic substrates. Low-temperature MOCVD of high-dielectric ceramic films will be developed to achieve lower voltage operation and higher luminescent efficiency. Spire's MOCVD oxide reactor is set up to deposit phosphor as well as high-dielectric materials, and Spire will also attempt to improve electroluminescent efficiency and lower fabrication costs by rapid deposition of multilayer dielectric-phosphor-dielectric stacks in the same reactor. This research will result in the capability to fabricate flat-panel EL displays on plastic substrates for rugged, bright, lightweight, handheld information terminals to provide better graphical communication to personnel in demanding environments. ***