Conical-Shaped Titania Nanotubes for Optimized Light Management in DSSCs Reach Back-side Illumination Efficiencies > 8%

TL;DR

This study introduces conical TiO2 nanotubes for dye-sensitized solar cells, significantly enhancing photon absorption and achieving back-side illumination efficiencies over 8%, surpassing conventional cylindrical nanotubes.

Contribution

The paper presents a novel anodic growth method for conical TiO2 nanotubes that improve light management in DSSCs, leading to higher efficiencies compared to traditional structures.

Findings

Back-side illumination efficiencies > 8%

60% higher efficiency with nanocone structures

Enhanced photon absorption demonstrated by FDTD modeling

Abstract

In the present work, we introduce the anodic growth of conical shaped TiO2 nanotube arrays. These titania nanocones provide a scaffold for dye-sensitized solar cell (DSSC) structures with significantly improved photon management, providing an optimized absorption profile compared with conventional cylindrical nanotube arrays. Finite difference time domain (FDTD) modelling demonstrates a drastically changed power-absorption characteristic over the tube length. When used in a back-side illumination DSSC configuration, nanocone structures can reach over 60 % higher solar cell conversion efficiency than conventional tubes. The resulting {\eta} of ca. 8 % represents one of the highest reported values for Graetzel type DSSCs used under back-side illumination.