Paper TF-ThA6
Resonant Infrared Pulsed Laser Deposition of Organic Materials for Display Applications

Thursday, November 12, 2009, 3:40 pm, Room B4

We report the resonant infrared pulsed laser deposition (RIR-PLD) technique for depositing novel, functional polymers, small organic molecules and nanoparticle-loaded polymers. Film deposition based on resonant infrared (RIR) laser ablation is enabled by resonant excitation of a localized, intra-monomer vibrational mode of the target material, such as a C-H stretch; this leads to low-temperature volatilization and deposition of undamaged small molecules, polymers and even nanoparticles. Because the mid-infrared photons used in this process have energies far below those required to break the bonds that connect monomer units, RIR laser irradiation ablates polymers without photofragmentation, unlike ultra-violet pulsed laser deposition (UV-PLD). In this paper, we will demonstrate successful RIR-PLD deposition of selected materials that are essential to organic light emitting diode (OLED) technology; (1) light emitting small-molecule and polymer materials such as Alq₃ (Tris(8-hydroxyquinolinato)aluminium), MEH-PPV and conducting polymer PEDOT:PSS (Poly(3,4-ethylenedioxythiophene) poly(styrene sulfonate)); (2) polymeric barrier film such as cyclic olefin copolymer (COC) and Teflon®; and (3) nanocomposite materials based on TiO₂ and metal nanoparticles that serve as brightness enhancement layers and transparent conducting electrodes.

The deposited films are characterized by SEM (scanning electron microscopy) and FTIR (Fourier-transform infrared spectroscopy), photo- and electroluminescence. We will also present the comparison of film properties as they depend on different mid-infrared laser choices, such as a picosecond, tunable free electron laser (FEL), Er;YAG laser and picosecond optical parametric oscillator (OPO).