Critical issues in enhancing brightness in thin film phosphors for flat-panel display applications

• Published in: Applied surface science Vol. 197; pp. 321 - 324
• Main Authors: Singh, R.K, Chen, Z, Kumar, D, Cho, K, Ollinger, M
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.09.2002
• Subjects: Europium-doped yttrium oxide; Field emission displays; Surface roughness; Thin film phosphors; Thin film phosphors; Surface roughness; Field emission displays; Europium-doped yttrium oxide
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/S0169-4332(02)00390-2

Thin film phosphors have potential applications in field emission flat-panel displays. However, they are limited by the lower cathodoluminescent brightness in comparison to phosphor powders. In this paper, we have investigated the critical parameters that need to be optimized to increase the brightness of phosphor thin films. Specifically, we studied the role of surface roughness and optical properties of the substrate on the brightness of the phosphor films. Thin Y 2O 3:Eu phosphor films were deposited on various substrates (lanthanum aluminate, quartz, sapphire, and silicon) with thicknesses varying from 50 to 500 nm. A model that accounts for diffuse and specular or scattering effects has been developed to understand the effects of the microstructure on the emission characteristics of the cathodoluminescent films. The results from the model show that both the optical properties of the substrate and the surface roughness of the films play a critical role in controlling the brightness of laser deposited phosphor films.