Red-green-blue polymer light-emitting diode pixels printed by optimized laser-induced forward transfer

Summary of the LIFT process for tri-color OLED pixels. The 1-D substrate architecture is shown for the LIFT donor substrate (a) and the receiver substrate (b). The transfer of the first OLED color, blue, is shown in detail with the laser beam approaching (c) and the TP ablation and pixel deposition (d). LIFT of the green (e) and red (f) OLEDs is shown in sequence, and EL operation of the final three colors, side-by-side is also shown (g).
Summary of the LIFT process for tri-color OLED pixels. The 1-D substrate architecture is shown for the LIFT donor substrate (a) and the receiver substrate (b). The transfer of the first OLED color, blue, is shown in detail with the laser beam approaching (c) and the TP ablation and pixel deposition (d). LIFT of the green (e) and red (f) OLEDs is shown in sequence, and EL operation of the final three colors, side-by-side is also shown (g).

Abstract:

An optimized laser-induced forward transfer (LIFT) technique has been used to fabricate tri-color organic light-emitting diode (OLED) pixels. At reduced pressures, and with a defined donor-receiver gap, patterned depositions of polyfluorene-based OLED pixels have been achieved. OLED pixel functionality has been demonstrated and compared with devices made using conventional deposition techniques. In addition, improved functionality has been obtained by coating the cathode with an electron-injecting layer, a process not possible using conventional OLED fabrication techniques. The OLED pixels fabricated by LIFT reach efficiencies on the range of conventionally fabricated devices and even surpass them in the case of blue pixels.

Keywords: Laser induced forward transfere; Laser printing; sequential laser deposition; organic light emitting diodes; triazene polymer; PLED pixels; thin-films; patterned deposition: laser direct-write;

Facility: ENE, EMPA, LMX, Thin Films and Interfaces

Reference: J. Shaw-Stewart, T. Lippert, M. Nagel, F. Nüesch, A. Wokaun; Appl. Phys. Lett. 100, 203303 (2012)

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