Enhanced thermal stability of optical nonlinearity for anilino–silane derived inorganic–organic hybrid thin films

A series of chromophore-bonded inorganic–organic hybrid films were successfully prepared via a sol–gel process using the alkoxysilane dye (ICTES-DR1), anilinomethyltriethoxysilane (AMTES) and tetraethoxysilane (TEOS) as precursors. Second-order NLO properties and their thermal stability of the hybrid films were investigated by in situ second harmonic generation (SHG) measurement. The poled films exhibit large second harmonic coefficient (d33) in the range of 32–41 pm/V at 1064 nm. The aniline group of the AMTES was found to be effective for improving the thermal stability of optical nonlinearity due to the formation of hydrogen bonds between the carbonyl and aniline group, which was confirmed by virtue of FTIR and UV–visible spectra.