Laser-Induced Forward Transfer of Organic LED Building Blocks Studied by Time-Resolved Shadowgraphy†

The patterned deposition of thin films is essential for many technological applications. One promising material deposition technique is laser-induced forward transfer (LIFT), where a thin layer coated on a transparent substrate is ablated by a laser pulse passing through the substrate. The ablated material is collected on a nearby receiver substrate in a pattern defined by the laser. The technique can be applied to heat and light sensitive materials, provided that they are not directly irradiated by the laser pulse. For this application, a sacrificial layer is introduced between the substrate and the transfer layer so that the laser energy is converted into mechanical propulsion while protecting the sensitive layer from radiation. In this work, the application of a triazene polymer as a sacrificial layer for LIFT has been studied with the final goal of transferring organic light-emitting diode (OLED) pixels. Donor films made of a stack of triazene polymer, metal, and optionally an electroluminescent polym...