The Study of Blocking Effect of Nb₂O₅in Dye-Sensitized Solar Cells under Low Power Lighting

Abstract

Suppression of charge recombination is an efficient strategy capable of improving the photovoltaic performance of dye-sensitized solar cells (DSSCs). Herein, we fabricate a Nb 2 O 5 thin film on a fluorine-doped tin oxide (FTO) photoanode using a facile dip-coating method and study its blocking effect on charge recombination under various illuminance. The results show that the blocking effect of Nb 2 O 5 is strongly illuminance intensity dependent. The blocking effect of Nb 2 O 5 is insignificant at strong (one sun, >100,000 lux) illumination because the suppressed reverse charge flux makes no substantial contribution to the high-level injection of photo-excited charges. Conversely, the blocking effect plays an important role in the efficiency improvement as the photon-injected charge flux significantly reduces at low-intensity illumination (300-6000 lux). The efficiency of DSSCs with a blocking layer can be improved by 10% to 53% under low-intensity illumination, and the efficiency improvement is attributed to an improvement in fill factor.

Review—Energy Autonomous Wearable Sensors for Smart Healthcare: A Review

“…The indoor ambient light is composed of natural light coming from outside, and artificial light provided by lamps or luminaries have typical irradiance ranges between 0.1-1 mW/cm 2 (depending on the distance between the light source and sensor). 204,205 Among many different types of solar cells investigated, amorphous silicon based or dye-sensitized solar cells 206 have advantage of higher absorption in the visible wavelength range. The harvested power densities using these solar cells range from 37.9 to 92.6 μW/cm 2 for bright indoor conditions.…”

Blocking the Charge Recombination with Diiodide Radicals by TiO2 Compact Layer in Dye-Sensitized Solar Cells

“…19,[38][39][40] Moreover, compact layers have been prepared by using Nb-doped TiO 2 41 and other materials such as ZnO [42][43][44] and Nb 2 O 5 . [45][46][47][48] Under short circuit conditions, the potential at the FTO electrode is identical to the redox potential of the electrolyte provided that a sufficiently electrocatalytic counter electrode is used. Although an electrochemical reduction reaction is possible at the FTO substrate as well, the recombination via the FTO substrate will be negligible due to the poor electrocatalytic properties of this substrate.…”