Effect of front-contact laser texturing in thin-film solar cells

ZnO:Al films of about 400 nm thick were deposited on glass substrates by a magnetron sputtering system. We used a diode-pumped solid-state laser (Nd:YVO4) working at 355 nm to texture the AZO films. The texture patterns used were: a simple pattern obtained by scribing parallel grooves with a constant spacing, and a crisscross pattern obtained with a second array of parallel laser scribes perpendicular to the first one. Varying the process parameters we obtained different morphologies, with scribes ranging from widely spaced to overlapping grooves, and from almost undamaged surfaces to scribes that reached the glass substrate. The light scattering produced by the textured ZnO:Al films was evaluated through the haze factor.