Array of dendritic TiO2 modified with Sb2S3 and its application in hybrid solar cells

Abstract

In order to provide multiple electron transmission channels and increase the load of narrow gap semiconductor and organic semiconductor, the array of TiO2 dendritic structure assembled by nanotube and nanowire is constructed on FTO glass by hydrothermal method. Narrow gap semiconductor Sb2S3 is fabricated on dendritic TiO2 successfully by chemical bath deposition (CBD) method. By means of SEM, XRD, UV visible absorption spectrum, transient photocurrent, steady-state fluorescence spectrum and J-V curve, the morphology, crystal shape, light absorption and photoelectric properties of the samples are characterized and tested. The effect of deposition time on power conversion efficiency (PCE) is further studied. The results show that sparse TiO2 dendritic structure formed vertical to the FTO substrate might be a benefit for the fast electron transport; the addition of Sb2S3 strengthens the absorption of visible light, improves the photocurrent intensity, increases the intensity of fluorescence quenching and facilitates the generation and transfer of photogenerated carriers; the PCE of hybrid solar cell (HSC) based on dendritic TiO2/Sb2S3/P3HT/PEDOT∶PSS/Au structure reaches 1.10%, and this PCE is 10 times that of the HSC without Sb2S3. The deposition of Sb2S3 on the multistage structure TiO2 is conducive to improving the absorption of visible light, strengthening the transmission capacity of the optical carrier, broadening the spectrum response range and improving the photoelectric performance. It is of great significance to solve the problems of weak absorption intensity and narrow spectrum response range of simple TiO2 electrodes.

Keywords

• electrochemistry
• dendrite TiO2
• Sb2S3
• chemical bath deposition (CBD) method
• hybrid solar cell