Influence of graphene oxide concentration on IDES capacitive humidity sensor response behavior

Abstract

—Capacitive type humidity sensor was fabricated on CMOS technology by lithography process base on silicon p-substrate with Nitride passivation layer and designed on interdigitage electrodes (IDEs). This paper proposed the influence of various stock graphene oxide (GO) concentrations on humidity sensor responses behavior by drop coating method. The Raman spectroscopy is demonstrated for GO presence and scanning electron microscope (SEM) is exhibited the GO surface morphologies. The capacitance value is examined under different relative humidity (RH) ranges at 0.30% to 80% RH. The IDEs capacitive humidity sensor shows linear, polynomial and exponential responses behaviors for high, medium and low stock GO concentrations, respectively. The high stock GO concentration is significantly improved all dominant humidity sensor properties, especially the sensitivity at low RH (10%, 20%, 30% and 40% RH) which is improved up to 6683.65%, 2097.27%, 1984.91% and 1465.93%, respectively. Furthermore, it shows linear responses behavior by 0.991 for coefficient of determination of wide RH. Moreover, the IDEs capacitive humidity sensors are comparatively examined response/recovery times, hysteresis as well as repeatability. Finally, high stock GO concentration of humidity sensor is exhibited under various temperature operating ranges (20-50 degree Celsius). It clearly demonstrates for alternative applicability to use on humidity sensor applications.