Speaker
Description
Indium tin oxide (ITO) is a transparent conductive oxide frequently used as electrode in numerous optoelectronic devices, such as thin film solar cells, organic LEDs and touch panels, as well as in gas and humidity sensors [1,2]. Surface microtexturing on ITO can be beneficial for enhancing the light trapping effect in solar cells, for improving the light outcoupling of OLEDs or for engineering the electrical resistance. Several studies have been focused on the laser scribing process of ITO with the end goal to electrically isolate the different layers in large area solar modules [3]. However, only a few works have explored the possibility to texture ITO surfaces with repetitive features using laser radiation. In this work, the Direct Laser Interference Patterning (DLIP) method was employed to structure the surface of 500 nm thick ITO films by overlapping two coherent beams emitted from a NIR (1030 nm) laser source with pulse durations between 266 fs and 15 ps. An innovative optical configuration was implemented, using an imaging approach as well as cylindrical lenses for generating an elongated laser beam with a spot size of 160 µm x 2000 µm . Here, the possibility is given to enable a high surface texturing throughput. Optical confocal microscopy and SEM analysis revealed uniform textures with well-defined parallel grooves characterized by a spatial period of 6 µm and a structure depth up to 450 nm. Conductive atomic force microscopy (CAFM) was used to characterize the variations in the electrical resistance in the peaks and valleys of the microtexture.
References
[1] Vaishnav V et al. Sensors Actuat. B: Chem. 206 381–8 (2015).
[2] Zhang D et al Enrgy. Proced. 8 207–13 (2011).
[3] Tseng S-F et al. Appl. Surf. Sci. 257 1487–94 (2010).
| Speaker Country | Germany |
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