Electrospray deposition of SnO₂ films from precursor solution

Abstract

The electrospray deposition (ESD) of SnO 2 films from SnCl 4 .5H 2 O precursor solution was performed for gas sensor applications. Deposition time, solution flow rate and solution concentration were the main control parameters in the ESD process. The morphological properties of the deposited films were characterised by scanning electron microscopy. X-ray diffraction and energy dispersive X-ray analyses were employed to confirm the crystal phases and composition of the films. The best coatings with an island of particle agglomerates were observed at a flow rate of 0.12 ml min −1 , for 60 min, and at a 0.05M concentration. The crystallisation of SnO 2 films was observed at 650°C. The grain size and surface morphology of the films were influenced by the sol concentrations. Larger grain size and cracked surface were observed by increasing the sol concentration. The film thickness of 6 µm and a grain size of less than 100 nm were achieved.

A comprehensive design schedule for electrosprayed thin films with different surface morphologies

“…Another factor that influences surface morphology is the precursor liquid concentration. According to Gürbüz et al (2016), an increase in concentration increases the film thickness which affects morphology. In their study, they electrosprayed SnO2 precursor in ethanol (boiling point of 78 °C) for 1 h at a substrate temperature of 250 °C.…”

“…With increasing time, the film thickens and the substrate surface is completely covered causing consecutive landing droplets to experience varying contact angles that alter the surface morphology. The effects of deposition time on surface morphology were investigated by Gürbüz et al (2016), who deposited 0.05 M SnO2 film from an ethanol precursor (boiling point of 78 °C) at a flow rate of 7.2 mL h −1 and at a substrate temperature of 250 °C for various time intervals. After 20 min, they observed that the substrate was sparsely covered because of the small number of deposited droplets.…”

A comprehensive design schedule for electrosprayed thin films with different surface morphologies

“…Another factor that influences surface morphology is the precursor liquid concentration. According to Gürbüz et al (2016), an increase in concentration increases the film thickness which affects morphology. In their study, they electrosprayed SnO2 precursor in ethanol (boiling point of 78 °C) at a substrate temperature of 250 °C for 1 h. Precursor concentrations were varied from 0.05 M to 0.2 M but flow rate was kept constant at 7.2 mL h −1 .…”

Electrospray Printing of Graphene Layers for Chemiresistive Gas Sensors

“…This drawback has been addressed through multiplex ES (MES) techniques, demonstrating the simultaneous operation of hundreds of ES sources and a remarkable packing density exceeding 10 4 sources/cm 2 [33]. Thin films of MOS and conductive polymers have been prepared by ES of precursor solutions or nanoparticle suspensions for gas sensing applications [34][35][36][37][38][39]. Only recently ES has received attention for the preparation of gas sensors based on graphene [40,41].…”