Microscopy from Scientific Research

Investigation via a scanning electron microscope (SEM) reveals the different drying characteristics after slot jet drying (left, green). Reproducible, slot jet-dried substrates contain i) homogeneous and dense thin film with grain sizes 2 m (optimal area, PCE = 18.7%, ii) areas with smaller grain sizes (PCE = 16.1%), and iii) inhomogeneous layers with pinholes and high roughness (97 nm, PCE = 12.9%). Investigation of the morphology via SEM reveals that grain sizes are significantly larger and densely packed for morphologies corresponding to better PCE values compared to the two differently definable morphology regions.

DOI