Preparation of polyperinaphthalenic organic semiconductive nanoparticles by excimer laser ablation and their application to optic and electronic devices

Abstract

Polyperinaphthalene (PPN) nanoparticles are prepared by excimer laser ablation (ELA) of a 3, 4, 9, 10-perylenetetracarboxylic dianhydride (PTCDA) target or a mixture target of PTCDA with Co or TiO2 powder (PTCDA/X: X=Co, TiO2) using XeCl excimer laser beams. Enhancement of elimination reaction of side groups of PTCDA is observed by ELA of PTCDA/Co and PTCDA/TiO2. In particular, for PTCDA/TiO2, the reaction occurs at a fluence of 0.25 J cm−2 pulse−1 much lower than the case of PTCDA/Co at room temperature. Heterojunctions between the PPN nanoparticle layer and Si wafers are formed. Well rectifier property is demonstrated for the junction with n-Si substrates. Current versus voltage curve of the heterojunction with a n-Si substrate in the dark and under illumination shows the possibility of the junction as a photovoltaic cell. Furthermore, PPN nanoparticles are applied to anode electrodes for ultrathin rechargeable Li ion batteries. In situ Raman spectroscopy under lithium ion doping is performed to elucidate the storage mechanism of lithium ion at cis-polyacetylene-type edge (phenanthrene-edge) of PPN structure.