The impact of trough geometry on film shape. A theoretical study of droplets containing polymer, for P-OLED display applications.

摘要: For P-OLED display fabrication, it is important to control the final film shape, arising from drying of volatile droplets containing polymer. Due peripheral pinning and subsequent outward capillary flow, a coffee-ring typically develops. This inconvenient since spatially uniform height, above substrate, required ensure current across device. Typically are deposited inside trough-like structure on substrate. We present thin-film lubrication model that tracks dynamics through shape. The governing equations derived solved numerically. investigate effect trough’s depth slope walls. Increasing or wall’s gradient increases formation. due an increase in horizontal velocity, caused by substrate’s shape as well delayed gelation latter allows flow act for longer time, before height becomes fixed.