  Dye Sensitized Solar Cells (DSSCs) have recently regained attention for
indoor light harvesting and powering wireless devices. Advantages such as
cost-effectiveness, flexibility, wide angular response, and lightweight design
have driven the fostering of the implementation of advanced photonic
architectures, dedicated photosensitizers and compatibility with wearable
carriers. However, to fully exploit their potential, crucial aspects require
further attention, in particular the improvement of spectral compatibility and
low-light harvesting mechanisms, as well as the development of efficient
photoanodes through high-yield scalable methods. In this article, we propose
the use of nanocomposite photoanodes integrating mesoporous TiO2 (m-TiO2)
nanoparticles, ITO nanotubes (NTs) and TiO2 anatase shells (ITO@TiO2 NTs)
prepared by step-by-step method relying on mild temperature conditions and
avoiding toxic precursors. These photoanodes outperform previous attempts to
implement low-dimensional ITO and ITO@TiO2 nanowires and nanotubes for outdoor
light conversion, demonstrating an outstanding PCE under low artificial light
intensity of 24 % for at 0.014 mWcm-2, a 166 % increase compared to the
conventional architectures. Advanced microstructural, optical, and
electrochemical characterizations have revealed that the strong scattering
effect of the light in the visible range coupled with enhanced charge
collection at low-intensity illumination are the essential mechanisms
responsible for such enhanced energy conversion. Remarkably, our devices retain
up to 90% of the normal incidence efficiency even under glancing illumination,
while conventional reference devices show a drop down to 50%.
