Synthesis and investigation of cubical shaped barium titanate and its application as opto-electronic humidity sensor

Abstract

In the current scenario, nanoscience and nanotechnology are playing a vital role in the upliftment of the quality of human life. The quantum confinement effect that arises at the nano-dimensional particles, changes the properties of the material in a drastic way. The present paper reports the successful synthesis of BaTiO3 using rotary evaporator and fabrication of sensing elements by deposition of films on flat borosilicate glass substrates using 2-methoxy ethanol and homogeneous precursor in the ratio of 1:4, 2:4, 3:4 and 4:4. These films were then annealed at 650 °C and characterized through various techniques. Morphological investigation as obtained from SEM reported the cubical clusters and the dimensionality of these clusters, decreases with increase in the concentration of 2-methoxy ethanol. An optical investigation done through UV–Vis spectrum showed the absorbance in the UV range and Tauc plot estimated the optical band gaps of 3.842, 3.854, 3.864 and 3.872 eV for the respective films. Structural information as obtained from XRD of the film having 2-methoxy ethanol and homogeneous precursor in the ratio of 4:4 gave minimum crystallite size of ~ 18 nm. Further, these films were employed as opto-electronic humidity sensor where the maximum sensitivity of the sensing elements was found as 2.15, 2.79, 3.28 and 3.67 µW/%RH respectively. Thus as the concentration of 2-methoxy ethanol in the solution increases, the properties of the material increases and hence the humidity sensing potency also increases.