Preparation and characterization of germanium dioxide nanostructure for gas sensor application: effect of laser parameters

In this article, a novel application of germanium dioxide (GeO2) as a gas sensor is systematically reported. In detail, GeO2 layers were deposited on quartz and n-type Si substrates, as a function of laser pulses, using combined laser ablation and thermal spray coating approaches. The attained layer/s were methodically inspected in term of their morphological, structural, and optical features; specifically, highly crystalline GeO2 structure was obtained for samples prepared using 1500 pulses and above. In the meanwhile, the obtained particle diameters were found to be within the range of 15 to 274 nm, while the estimated optical band gaps exhibited values from 3.85 to 4.0 eV. Simultaneously, the gas sensing behavior demonstrated a well-oriented performance for all devices, however, devices treated with 2500 pulses delivered stable trend with sensitivity value as high as 3 × 10−6. The rise/fall period revealed an adequate outcome (~10 𝑠𝑠𝑠𝑠𝑠𝑠.) for gas sensors fabricated via pulses of 1000 and above, with respected to the working temperature. The proposed framework delivers a substitute technique towards 2D metal oxide based eco-friendly-gas sensor.