A novel research approach on the dynamic properties of photogenerated charge carriers at Ag2S quantum-dots-sensitized TiO2 films by a frequency-modulated surface photovoltage technology

Ag2S quantum-dots-sensitized TiO2 films with different amount of Ag2S were fabricated by a successive ionic layer adsorption and reaction (SILAR) method. The separation and transport of photogenerated charge carriers at different spectral regions were studied by the frequency-modulated surface photovoltage technology. Some novel dynamic information of photogenerated charge carriers in a wide spectral range is found. The results indicate that the rate and direction of separation (diffusion) for photogenerated charge carriers are closely related to the performance of quantum-dots-sensitized solar cells (QDSSCs) based on the Ag2S/TiO2 nano-structure.