ZnO Thin Film Processed by Direct Laser Interference Patterning for Formaldehyde Detection

Direct laser interference patterning (DLIP) is a fast nanostructuring technique able to generate periodic patterns in the submicrometric range, what modifies the morphology and structural properties of semiconductors. DLIP has been used on gas sensors based on ZnO thin film, generating 1D patterns. The nanostructuring has modified the crystal structure and the surface topography. DLIP acts similarly to a thermal treatment from the crystallographic point of view and has been used to detect low concentration of formaldehyde (HCHO). Comparable magnitude of responses (around the 25 % for 20 ppm of formaldehyde) are shown for sensors thermally treated sensors and sensors processed by DLIP.