Optimal ablation of fluorine-doped tin oxide (FTO) thin film layers adopting a simple pulsed Nd:YAG laser with TEM00 mode

In material processing, a laser system with optimal laser parameters has been considered to be significant. Especially, the laser ablation technology is thought to be very important for fabricating a dye-sensitized solar cell (DSSC) module with good quality. Moreover, the TEM00 mode laser beam is the most dominant factor to decide the incident photon to current conversion efficiency (IPCE) characteristics. In order to get the TEM00 mode, a pin-hole is inserted within a simple pulsed Nd:YAG laser resonator. And the spatial field distribution is measured by using three pin-hole diameters of 1.6, 2.0 and 4.0 mm, respectively. At that moment, each case has the same laser beam energy by adjusting the discharge voltage and pulse per second (pps). From those results, it is known that the pin-hole size of 1.6 mm has the perfect TEM00 mode. In addition, at the charging voltage of 1000 V, 10 pps, the feeding speed of 6.08 mm/s and the overlapping rate (OL) of 62%, the scanning electron microscope (SEM) photograph of fluorine-doped tin oxide (FTO) thin film layers shows the best ablation trace.