N, La Co-Doped TiO₂for Use in Low-Temperature-Based Dye-Sensitized Solar Cells

In this survey, N, La co-doped TiO2 nanocrystals are synthesized through simple sol–gel method. Results reveal that both elements of N and La are introduced successfully into the structure of TiO2 and exist as the form of La (Ti–O–La) bonds, N (N–Ti–O) bonds and N (Ti–O–N) bonds by several characterization analysis, thereby resulting in the formation of new impurity energy level between the forbidden bands, and great enhancement of light absorption ability in visible light region. These resulting samples are fabricated for low-temperature-based dye-sensitized solar cells (DSSCs), and the highest temperature of the whole process is 120°C. EIS, Bode plot and I-V analysis are employed to measure photovoltaic performance of DSSCs. The photoelectric conversion efficiency (η) of DSSCs with co-doped TiO2 materials as the photoanode is 5.33%, and when compared to pure TiO2-based cell (4.02%), the η is increased by 32.6%.