Synthesis and characterization of CTAB-assisted WO3 deposited on silicon for the fabrication of photoresponse p-n junction diode

Abstract

The promising semiconductor material of tungsten trioxide (WO3) prepared by two wet chemical route such as solvent evaporation and precipitation method by using sodium tungstate dihydrate as starting material. The structural, optical and electrical characterizations of n-WO3/p-Si semiconductor diode have been investigated. The XRD pattern exposed that monoclinic structure occurs at 400°C. FESEM revealed that the morphologies of WO3 particles were square with coarse and sponge like structure. The formation of WO3 was confirmed by vibration spectra of FT-IR. UV–vis spectroscopy shows that the band gap values are found to be 2.47 and 2.56eV. DC conductivity of WO3 was studied as a function of temperature, which exhibits the semiconducting nature. Dielectric properties such as dielectric constant (ε′), dielectric loss tangent (tan δ) and AC conductivity were measured as a function of frequency in the range from 50Hz to 5MHz at different temperatures. The conducting mechanism of n-WO3/p-Si diode was observed under light on/off condition. We concluded morphology of chemical precipitation sample favored for good optical band gap, electrical and photoresponse conductivity from solvent evaporation sample.