Carbon surface modification of silicon nanowires for sensing application

Abstract

The silicon nanowires were produced by a two-step metal-assisted chemical etching (MACE) technique. The surface modification of the SiNWs array with carbon modifiers (fullerene, multiwalled carbon nanotubes, graphene) was carried out by the drop-casting technique. Sensors of physical quantities (temperature, light, and humidity) were obtained on the basis of such hybrid structures. The surface morphology of the modified SiNWs array was investigated by atomic force microscopy. Chemical analysis of the hybrid structures was performed by X-ray diffraction and X-ray fluorescence analysis. The effect of the modification parameters (type and content of the modifier) of the SiNWs array on two different substrates (with a resistivity of 1 and 10 Ω·cm) on the static and dynamic parameters of such sensors was determined. In particular, the maximum response value for temperature sensors was 22.7·10³, and the response/recovery time was 0.15/0.74 s, respectively. For the light sensors, the maximum response value was 98, and the response/recovery time was 0.018/0.06 s, respectively. In turn, the maximum response value for humidity sensors was 19, and the response/recovery time was 11.5/3.3 s, respectively. These sensors can be used for complex monitoring of human health and technological processes in industry.