Enhanced overall conversion efficiency of dye-sensitized solar cells using nano-hollow patterns for efficient light scattering

Dye-sensitized solar cells (DSSCs) have attracted great attention due to their distinct efficiency, very low fabrication cost, good performance under diffuse light condition, and ability to be fabricated on flexible substrates. One of the main efficiency-limiting factors of DSSCs is the poor light absorption of dye molecules at longer wavelengths. In this work, we formed cylindrical nano-hollow patterns (CNHPs) between the TiO2 nanoparticle (TNP) film and the front transparent electrode by using the direct printing technique and etching process to improve the light absorption of dye molecules at longer wavelengths. In addition, optical properties such as diffused transmittance and light absorption were measured by using UV-visible spectrometer. Optical characterizations of the TNP films with CNHPs revealed strong light scattering within the wavelength range of ∼600 ∼800 nm Owing to the light scattering effect provided by the CNHPs formed in the TNP films, increases in the short-circuit photocurrent density and overall conversion efficiency of the DSSCs were observed.