Thin-Film panels are actually comprised of a large number of thin 'cells' - or strips - that are interconnected to allow low-voltages to be added up in series across the panel, while keeping the current generated from the panel at a low level of a few amps. Dividing up these panels into cells involves the use of lasers to 'pattern' the layers during the Thin-Film deposition stages. Lasers have been the preferred technology for Thin-Film Patterning from the inception of Thin-Film production over ten years ago. As a result, this application for lasers within the Solar industry represents the area where lasers are most commonly used and have the highest visibility levels.
Each of the common Thin-Film absorber-types (a:Si, CIGS, Cd:Te) requires three Patterning stages (termed P1, P2, and P3). While a range of different materials is found across Thin-Film manufacturing, the Patterning steps are most typically performed with relatively low-power (up to 20W) short-ns-pulsewidth diode-pumped solid-state lasers, either at 1064, 532, or 355 nm. The choice of wavelength is typically due to the absorption properties of the materials used. Decreasing the pulsewidths can provide cleaner selective material removal: increasing the repetition rates can increase the process time on larger panel sizes.