Hierarchically Structured ZnO Film for Dye‐Sensitized Solar Cells with Enhanced Energy Conversion Efficiency

Abstract

A hierarchically-structured ZnO film consisting of secondary colloidal spheres of ~ 300 nm in diameter and primary nanoparticles of ~ 20 nm in diameter is shown to have an ~ 83% improvement in the overall light conversion efficiency, when compared to commercially-obtained ZnO film with ~ 25 nm particles. This increase is attributed to the hierarchical structure, where the secondary colloidal spheres promote light scattering for enhanced photon absorption.