Ventajas: efficient, low cost, high throughput
film deposition technique
Meniscus coating can be defined as the translation of a
meniscus over the surface of a substrate as the solution is
spread by the coating tool.
Factores importantes: forma y flujo de
solución en el menisco, velocidad de secado durante y
después de deposición
Advancing meniscus: wetting dynamics
determine coating speed. Verify straight
and steady wetting line! Refs 42 y 43
Variables claves: velocidad de
wetting line y ángulo de
contacto dinámico. Hallar Vcrit.
Receding Meniscus: its dynamics
significantly influences the film quality
Flujos: a) Couette (en dirección al movimiento). b) Delta
P entre meniscos. c) Marangoni Flow (surface tension gradients)
Técnicas de control: surfactantes,
calentamiento sustrato
coating regimes
Evaporation: drying speed similar
to coating speed. Drying in the
meniscus area
The film thickness decreases as increasing the coating
speed due to shorter residence time per unit length,
leading to a reduced amount of dried material. Highly
oriented films. Ejemplo: roll to roll del NREL con Ma/acn
hechas por roller a 2 m/min
Landau-Levich: drying slower than coating speed. wet film is formed and
remains. Desde 0.6 m/min es Landau en solvente DMF. En acn es evaporation
incluso a 2 m/min?