Laser Structuring of Organic Optoelectronic Devices

The future promise of organic electronics for a cheap production from solution has led to
large investments in research and development. To take the research devices from lab scale
to the market, the structuring of them is necessary to connect the devices monolithically to
decrease the resistance losses on the devices. Ultrashort pulsed lasers have been used for this
purpose in organic photovoltaic. They have also been used to structure the indium tin oxide
(ITO) layer in different geometries for its application in other type of devices like organic
light emitting diodes (OLEDs).
In this work the use of ultrashort pulsed lasers is investigated. Initially, the structuring of
ITO on a mechanically flexible polyethylene substrate is studied. The ablation with different
wavelengths is explored. The ablation was then optimized to structure lines with low bulges
and selective ablation with negligible damage to the PET layer below. The structured lines
were optimized with different wavelengths in the visible regime.
The ablation to monolithically connect OLEDs is then investigated. Devices with small
inactive areas that can be concealed by the illumination were manufactured. ... mehrThe power and
current efficiencies of these devices were improved by the decrease of the current and power
losses on the devices. The structuring was optimized with two different wavelengths.
In the next chapter, the structuring of OPV modules on ITO/glass substrates is explored.
Different materials forming the active layer are investigated, demonstrating the feasibility
of using the ultrashort pulsed lasers to structure modules with different active layers. The
structuring of tandem devices was also explored successfully fabricating working solar modules.
Finally, a method to experimentally optimized the solar cell width was investigated.
In the last two chapter two different all-solution OPV architectures (semitransparent and
opaque) are explored. The structuring was explored for different wavelengths in the visible
regime. Solar modules were then successfully manufactured. In both cases the structuring
of the bottom electrode (PEDOT:PSS or silver) is essential as high bulges might lead to
shortened devices.
All the processes investigated in this work are an important step for the future fabrication
of OPV and OLEDs.