EVALUATION ON THE EGFET PH SENSING PERFORMANCE OF SOL-GEL SPIN COATED TITANIUM DIOXIDE THIN FILM

• Main Authors: Abdullah, WFH (Author), Herman, SH (Author), Rahman, RA (Author), Rosli, AB (Author), Yusof, KA (Author), Zulkefle, MA (Author), Zulkifli, Z (Author)
• Format: Article
• Language: English
• Published: 2021
• Subjects: DRIFT; EGFET; pH sensors; sol-gel spin coating; thickness; thin films; titanium dioxide
• Online Access: View Fulltext in Publisher

 For this study, TiO2 thin film was fabricated using sol-gel spin coating method. The fabricated film was then applied as sensing membrane in an extended gate field effect transistor (EGFET) pH sensor system. The pH sensing performance of the sol-gel spin coated TiO2 were evaluated in terms of sensitivity, linearity and hysteresis where the value obtained was 58.70 mV/pH, 0.9922 and 86.17 mV respectively. The drift rate of the sample when being measured for 12 consecutive hours was also determined where measurement in pH 4, pH 7 and pH 10 yield drift rate of 1.72 mV/h, 4.14 mV/h and 6.05 mV/h respectively. Besides that, the TiO2 was characterized for its thickness (24.32 nm) and surface roughness (5.129 nm). From the results obtained, it was found that sol-gel spin coated TiO2 thin film with thickness between 20 - 29 nm will have high pH sensitivity (more than 50 mV/pH).