Morphology-driven electrical and optical properties in graded hierarchical transparent conducting Al:ZnO

Graded Al-doped ZnO layers, constituted by a mesoporous forest-like system evolving into a compact transparent conductor, were synthesized by Pulsed Laser Deposition with different morphologies to study the correlation with functional properties. Morphology was monitored by Scanning Electron Microscopy images and by measuring the resulting surface roughness. Its effects on electrical conductivity – especially carrier mobility, which significantly decreases with increasing roughness – allow to discuss the limitations in conduction mechanisms. Significant changes in light scattering capability due to variations in morphology are also investigated and discussed to study the correlation between morphology and functional properties.