Chemical structure change of thin films prepared from nonpolymeric organic compounds by pulsed laser deposition

Thin films from six kinds of nonlinear optical nonpolymeric organic compounds were prepared by pulsed laser deposition (PLD) using a KrF excimer laser (248 nm) at various fluences up to 50 mJ/cm2. Changes in the chemical structure of the films with changes in fluence were studied. The experimental results show that for every compound at least minor decomposition has already started at the threshold fluence for deposition. More serious degradation occurs with increasing fluences, and little of the original chemical structure remains in films prepared by PLD at a fluence of 50 mJ/cm2.