Structural and Optical Properties of Smooth Surface TCO Thin Films Deposited on Different-Sized Staked Nanoparticle Layers for Window Electrode of Thin Film Si Solar Cells

Abstract

To improve the light-scattering capacity of transparent conductive oxide (TCO) films without increasing in surface roughness, we formed a stacked nanoparticle layers of ZnO (NP-ZnO) and TiO₂ (NP-TiO₂), which serve as light-scattering and surface-modifying layers, respectively, between the glass substrate and low-resistive TCO layers. The stacked TCO/NP/glass (NP-TCO) substrate indicated strong light-scattering capacity, with a relatively low surface root mean roughness of approximately 10 nm. In addition, the haze value of NP-TCO substrates increased with an increase in the component particle diameter of the underlying NP-ZnO layers from about 20% (33 nm) to 40% (96 nm) at a wavelength of 550 nm.