Infrared reflection-absorption spectroscopy of Alq3 thin film on silver surface using synchrotron radiation

Infrared reflection-absorption spectra of Alq(3) film on Ag surface have been measured as a function of thickness in the wave number region from 300 to 500 cm(-1) using synchrotron radiation to determine which of the geometrical isomers of Alq(3) is dominant. The observed spectra of the Al-N stretching modes of Alq(3) indicate that Alq(3) film predominantly consists of the meridional isomer including the first monolayer adsorbed on the Ag surface. In the spectrum of the monolayer Alq(3), the Al-N stretching mode was observed to be located at wave number slightly lower than that of multilayer Alq(3) probably due to the charge transfer between Alq(3) and the Ag surface.