I. Introduction
High dielectrics play a very vital role in biosensor applications. Due to its good compatibility with nanomaterials like graphene and carbon nanotubes, it can be used as insulating as well as gate oxide layer in CNTFET devices [1, 3, 8]. Zirconia (ZrO2) is technologically an important material due to its high dielectric constant, good thermal and chemical stability and excellent mechanical properties [1, 2]. As further scaling of silicon based MOSFETs is not possible, integration of high dielectric materials with nanomaterials like carbon nanotube opens a new route towards device miniaturization [4, 10, 14, 15]. Due to this reason, suitable methods for the deposition of ZrO2 layers on substrates like ITO coated glass are being researched. Methods that are commonly used for depositing zirconia layers on conductive surfaces are vacuum evaporation, sputtering and electrophoresis [7, 9, 12]. The ECD approach is only possible in the case of electrolysis in molten salts. ECD of dielectrics like zirconia and hafnia is a very attractive area of study as it is most economical and simple way of controllable deposition of oxide layers on various conductive substrate. Reproducibility is one of the major advantages of the electrochemical deposition. From an electrochemical point of view there are few difficulties with the ECD of zirconia layers in aqueous electrolytes [11]. The rapid hydrolysis formation of polymeric chains and high electro generation causes local increase in pH near the cathode which is responsible for low adhesion of the deposited layer [2]. High rate of electrodeposition often damages the ITO substrate due to high flow of electrons. Various chemical reaction taking place during deposition [2, 7] \begin{align*}\mathrm{O}_{2}+2 \mathrm{H}_{2} \mathrm{O}+4 \mathrm{e}^{-} \rightarrow 4 \mathrm{OH}^{-}\tag{1}\\2 \mathrm{H}_{2} \mathrm{O}+2 \mathrm{e}-\rightarrow \mathrm{H}_{2}+2 \mathrm{OH}^{-}\tag{2}\\\mathrm{Zr} - \mathrm{OH}+ \mathrm{OH}^{-} \rightarrow \mathrm{Zr}- \mathrm{O}^{-} + \mathrm{H}_{2}\mathrm{O}\tag{3}\end{align*}