triazene polymers; laser ablation transfer; photodecomposition; time resolved shadowgraphy; organic thin films; spin coating; laser ablation; laser deposition; pixel; dynamic release layer; photo-decomposition; organic light-emitting devices; organic electronics; laser ablation; organic light-emitting devices; patterning; laser ablation transfer; conjugated polymers; triplet emitters
Stewart James Shaw, Lippert Thomas, Nagel Matthias, Nuesch Frank, Wokaun Alexander (2012), Red-green-blue polymer light-emitting diode pixels printed by optimized laser-induced forward transfer, in Applied Physics Letters
, 100(20), 203303.
Shaw-Stewart J, Chu B, Lippert T, Maniglio Y, Nagel M, Nuesch F, Wokaun A (2011), Improved laser-induced forward transfer of organic semiconductor thin films by reducing the environmental pressure and controlling the substrate-substrate gap width, in APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
, 105(3), 713-722.
Frank P, Shaw-Stewart J, Lippert T, Boneberg J, Leiderer P (2011), Laser-induced ablation dynamics and flight of thin polymer films, in APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
, 104(2), 579-582.
Shaw-Stewart J, Lippert T, Nagel M, Nuesch F, Wokaun A (2011), Laser-Induced Forward Transfer of Polymer Light-Emitting Diode Pixels with Increased Charge Injection, in ACS APPLIED MATERIALS & INTERFACES
, 3(2), 309-316.
Palla-Papavlu A, Paraico I, Shaw-Stewart J, Dinca V, Savopol T, Kovacs E, Lippert T, Wokaun A, Dinescu M (2011), Liposome micropatterning based on laser-induced forward transfer, in APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
, 102(3), 651-659.
Palla-Papavlu A, Dinca V, Luculescu C, Shaw-Stewart J, Nagel M, Lippert T, Dinescu M (2010), Laser induced forward transfer of soft materials, in JOURNAL OF OPTICS
, 12(12), 124014-124019.
Fardel R, Nagel M, Nuesch F, Lippert T, Wokaun A (2010), Laser-Induced Forward Transfer of Organic LED Building Blocks Studied by Time-Resolved Shadowgraphy, in JOURNAL OF PHYSICAL CHEMISTRY C
, 114(12), 5617-5636.
Stewart James Shaw, Lippert Thomas, Nagel Matthias, Nüesch Frank, Wokaun Alexander (2010), Laser-Induced Forward Transfer Using Triazene Polymer Dynamic Releaser Layer, in International Symposium on High Power Laser Ablation 2010
, Santa FeAmerican Institute of Physics, Melville, USA.
Dinca V, Fardel R, Shaw-Stewart J, Di Pietrantonio F, Cannata D, Benetti M, Verona E, Palla-Papavlu A, Dinescu M, Lippert T (2010), Laser-Induced Forward Transfer: An Approach to Single-Step Polymer Microsensor Fabrication, in SENSOR LETTERS
, 8(3), 436-440.
Palla-Papavlu A, Dinca V, Paraico I, Moldovan A, Shaw-Stewart J, Schneider CW, Kovacs E, Lippert T, Dinescu M (2010), Microfabrication of polystyrene microbead arrays by laser induced forward transfer, in JOURNAL OF APPLIED PHYSICS
, 108(3), 033111-033117.
Stewart J. Shaw, Fardel R., Nagel M., Delaporte P., Rapp L., Cibert C., Alloncle A. -P., Nuesch F., Lippert T., Wokaun A. (2010), The effect of laser pulse length upon laser-induced forward transfer using a triazene polymer as a dynamic release layer, in Journal of Optoelectronics and Advanced Materials
, 12(3), 605-609.
Fardel R, Nagel M, Nuesch F, Lippert T, Wokaun A (2009), Energy Balance in a Laser-Induced Forward Transfer Process Studied by Shadowgraphy, in JOURNAL OF PHYSICAL CHEMISTRY C
, 113(27), 11628-11633.
Fardel R, Urech L, Lippert T, Phipps C, Fitz-Gerald JM, Wokaun A (2009), Laser ablation of energetic polymer solutions: effect of viscosity and fluence on the splashing behavior, in APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
, 94(3), 657-665.
Seyfang BC, Fardel R, Lippert T, Scherer GG, Wokaun A (2009), Micro-patterning for polymer electrolyte fuel cells: Single pulse laser ablation of aluminum films from glassy carbon, in APPLIED SURFACE SCIENCE
, 255(10), 5471-5475.
Kaur KS, Fardel R, May-Smith TC, Nagel M, Banks DP, Grivas C, Lippert T, Eason RW (2009), Shadowgraphic studies of triazene assisted laser-induced forward transfer of ceramic thin films, in JOURNAL OF APPLIED PHYSICS
, 105(11), 113119-1-113119-9.
Fardel R, Nagel M, Nuesch F, Lippert T, Wokaun A (2009), Shadowgraphy investigation of laser-induced forward transfer: Front side and back side ablation of the triazene polymer sacrificial layer, in APPLIED SURFACE SCIENCE
, 255(10), 5430-5434.
In the preceding SNF project No. 200021-107666 entitled “Patterned Polymer Multilayer Light-Emitting Device Fabrication using Laser induced Forward Transfer” we have succeeded in the detailed characterization of the polymer ablation of thin films and detected a clear influence of the film thickness on the ablation threshold which we could model in detail by considering the laser penetration depth and heat conductivity of the substrate. This has then been the basis for the transfer of organic light-emitting device (OLED) materials using thin triazene layers as dynamic release layers. The transfer was performed successfully for a bi-layer system consisting of the OLED polymer MEH-PPV and an aluminum electrode. We demonstrated a successful transfer of a simple OLED structure onto conducting glass substrates and assessed that the performance of the laser deposited devices was equivalent to devices fabricated by spin-coating. Under the experimental conditions used in this study, we observed that the transfer was only possible within a relatively small fluence window. To fully understand and optimize the process both fundamental and applied research is required. A primary goal is to study the laser transfer process in more depth. Among other issues, the gap distance between donor and acceptor and the pressure dependence of the surrounding atmosphere shall be ad-dressed. The transfer of a single polymer layer which eventually permits versatile multilayer fabrication has to be established. Industrially relevant solid-state lasers shall also be evaluated for the transfer process. Finally, efficient state-of-the-art diodes shall be demonstrated using either polymers or small organic molecules. From a fundamental point of view we want to understand the ablation process in more depth. The dependence of the transfer characteristics, e.g. flyer speed and shape, as a function of laser parameters (fluence, wavelength, pulse length, beam profile) and surrounding gas pressure is of utmost interest to develop a model for triazene based laser transfer. The fate of the triazene release layer as well as the chemical and structural properties of the transferred layer are central to understand and elaborate the proposed transfer method. Ripple structure formation observed during the laser pulse are still not fully explained. The limitations regarding the pixel size that can be transferred have to be explored. From the mechanistic point of view it is still under debate whether the ablation process is mainly governed by a photochemical reaction, a thermal reaction or both. Future investigations looking at the intensity dependence of photodegradation of triazene polymers with different chemical compositions shall shed light on this matter.