Mapping of molecular C17 indandione-1,3 pyridinium betaine adsorbates on fused silica by surface second harmonic generation

Surface second harmonic generation (SHG) has been utilized to obtain information such as orientation, concentration distribution and desorption of C17 indandione-1,3 pyridinium betaine (IPB) thin films prepared by the Langmuir-Blodgett (LB) technique on fused silica. Data for C17 IPB adsorbate distribution after irradiation by several pulses of 1064 nm laser at 8 × 108 W/cm2 are described using a laser induced thermal desorption model. The results indicate that SHG is a useful tool for the determination of the concentration profile of adsorbates on surfaces with a submonolayer level sensitivity.