WO3 processed by direct laser interference patterning for NO2 detection

Laura Parellada-Monreal (1) , Sandro Gherardi , Giulia Zonta (2) , Cesare Malagù (2) , Davide Casotti (2, 3) , Giuseppe Cruciani (2) , Vincenzo Guidi (2, 3) , Miguel Martínez-Calderón (1) , Irène Castro-Hurtado (1) , Daniel Gamarra (4) , Jesus Lozano (4) , Lionel Presmanes (5) , Gemma García Mandayo (1)

1 UNAV - Universidad de Navarra [Pamplona]
2 UniFE - Università degli Studi di Ferrara = University of Ferrara
3 INFN - Istituto Nazionale di Fisica Nucleare
4 UEX - Universidad de Extremadura - University of Extremadura
5 CIRIMAT - Centre interuniversitaire de recherche et d'ingenierie des matériaux

In this paper two kind of sensors based on WO3 sputtered by magnetron sputtering and annealed at 600 °C have been studied. The first kind was processed by two-dimensional direct laser interfering patterning (DLIP) and the second one without any additional treatment. Morphological and structural characterization have shown a hole structure in a periodic line-pattern for the DLIP-processed sensors and a flat surface for the only-annealed sensors, both with a tetragonal WO3 phase. TOF-SIMS analysis has revealed that the first WO3 layers are reduced for both samples, which could improve sensing performance. Promising response enhancement of DLIP-processed sensors has been observed for low concentrations of NO2 (from 0.5 ppm to 5 ppm) at 200 °C, lowering the limit of detection (LOD) to 10 ppb, half of the LOD of the only-annealed sensors (20 ppb). Cross sensitivity to CO and HCHO have been investigated and the sensing mechanisms discussed.

Mots clés: WO3; DLIP; Tetragonal phase; TOF-SIMS; NO2; Arrhenius

Domaines: Chimie analytique; Matériaux; Micro et nanotechnologies/Microélectronique

Laura Parellada-Monreal, Sandro Gherardi, Giulia Zonta, Cesare Malagù, Davide Casotti, et al.. WO3 processed by direct laser interference patterning for NO2 detection. Sensors and Actuators B: Chemical, 2020, 305, pp.127226. ⟨10.1016/j.snb.2019.127226⟩. ⟨hal-03216944⟩