Towards the thermal stability of dye-sensitized solar cells for wavelength-selective greenhouses using the polymorphism of light-scattering layers

Using laboratory-size yellow dye-sensitized solar cells based on iodide/triiodide redox electrolytes, the effect of light-scattering layers on the thermal stability of these cells was studied up to 60 degrees C. In this work, the effect of the light-scattering layer and its polymorphism on the thermal stability is explored for the first time, opening a new perspective to achieve the long-term thermal stability of dye-sensitized solar cells under real conditions. Moreover, the commercial yellow dye was studied from the point of view of its thermal stability at the TiO2/dye/electrolyte interface. Due to the dual function of the yellow dye in our DSSCs, namely, as a photosensitizer and as a UV filter, an electrolyte with a high I3- concentration was used, which simultaneously favored a good photovoltaic efficiency and thermal stability. Herein, the dual function of the light-scattering layer was highlighted; the improvement of photon harvesting and the stability of yellow dye anchored on a rutile polymorph allow us to achieve excellent temperature coefficients for the short circuit current (+0.38%/degrees C) and the maximum power factor (-0.22%/degrees C), superior or comparable to other commercial generations of solar cells. Long-term thermal stability of DSSC was firstly highlighted by exploring the photoanode polymorphism.