Abstract:
This research proposed strategies to improve the stability of PSCs by means of the interface engineering between the electron transport layer (Titanium dioxide, TiO2) and the perovskite active layer [FA0.83Cs0.17Pb(I0.83 Br0.17 )3] by inserting the self-organic assembled monolayers (SAMs).The derivatives of Triethoxy (4-methoxyphenyl)silane (SAM1) and Triethoxy(3,4-dimethoxyphenyl)silane (SAM2) were synthesized using Grignard reaction. The Gaussian calculation results revealed that the structure of SAM1 has stronger dipole moment than that of SAM2. Both SAM1- and SAM2-coated TiO2 films showed an increased hydrophobicity property compared to uncoated TiO2 films. Band gap of the TiO2-SAM1 composite film appeared narrower than that of TiO2-SAM2 and untreated TiO2 films. In the preliminary electrical property tests of PSC devices, a significant increase of current density (Jsc) by 75% was found in case of SAM1-based PSC compared to unmodified PSC. Furthermore, the stability test results by mean of UV-VIS absorption spectra confirmed that the decomposition of perovskite has not been observed in case of TiO2-SAM1/FA0.83Cs0.17Pb(I0.83 Br0.17)3 composite film after 14 days storage in the dark. While the change in absorption spectra has been clearly observed after 4 and 12 days for the TiO2-SAM2/FA0.83Cs0.17Pb(I0.83 Br0.17)3 and unmodified-TiO2/FA0.83Cs0.17Pb(I0.83 Br0.17 )3 composite films, respectively.