Ablation of metal-containing perylene tetracarboxylic dianhydride with third harmonic of Nd:YAG laser

Deposited films were prepared by ablation of disk-like targets of 3,4,9,10- perylenetetracarboxylic dianhydride (PTCDA) and mixed targets of PTCDA with cobalt (PTCDA-Co) and copper powders (PTCDA-Cu) using the third harmonic of a Nd:YAG laser (355 nm) at fluences ranging from 0.1 to 1.0 Jcm ^-2pulse^-1. FT-IR and Raman spectroscopy showed that ablation of PTCDA-Cu at more than 500 mJcm^-2pulse^-1 led to an effective elimination reaction of the anhydride groups of PTCDA as well as PTCDA-Co at more than 700 mJcm^-2pulse^-1. In ablation of PTCDA-Co and PTCDA-Cu, plasma emission was observed around 500 nm. With increasing fluence, addition to the plasma emission, peaks at 437, 469, 513 and 550 nm coming from C₂ radicals were observed, suggesting that PTCDA was partially decomposed into C₂. TOF mass spectra in ablation of PTCDA-Co showed fragments of PTCDA without one or two anhydride groups as well as CoC_n⁺ (n0-5) and Co (CO)₂⁺.