Abstract
Photopyroelectric (PPE) spectroscopy is a nondestructive tool that is used to study the optical properties of the ceramics (ZnO + 0.4MnO2 + 0.4Co3O4 + xV2O5), x = 0–1 mol%. Wavelength of incident light, modulated at 10 Hz, was in the range of 300–800 nm. PPE spectrum with reference to the doping level and sintering temperature is discussed. Optical energy band-gap (Eg) was 2.11 eV for 0.3 mol% V2O5 at a sintering temperature of 1025 °C as determined from the plot (ρhυ)2 versus hυ. With a further increase in V2O5, the value of Eg was found to be 2.59 eV. Steepness factor ‘σA’ and ‘σB’, which characterize the slope of exponential optical absorption, is discussed with reference to the variation of Eg. XRD, SEM and EDAX are also used for characterization of the ceramic. For this ceramic, the maximum relative density and grain size was observed to be 91.8% and 9.5 μm, respectively.
Highlights
ZnO based ceramic semiconductors are widely used as gas sensors [1], piezoelectrics, electrodes for solar cells, phosphors, transparent conducting films and varistors [2]
The optical absorption behavior of ZnO doped with MnO2, Co3O4 is discussed for the different doping levels of V2O5 at different processing conditions
Samples doped at 0.3 mol% V2O5 contain the secondary phases Zn3(VO4)2, Zn4V2O9
Summary
ZnO based ceramic semiconductors are widely used as gas sensors [1], piezoelectrics, electrodes for solar cells, phosphors, transparent conducting films and varistors [2]. Sci. 2011, 12 absorption capability against various surges They are extensively used as protective devices to regulate transient voltage surges of unwanted magnitudes due to their fast response to over voltage transients. Varistors are formed with small amounts of other metal oxides such as Al2O3, Bi2O3, Co3O4, Cr2O3, MnO, Sb2O3, TiO2, etc. Such additives are the main tools that are used to improve the non-linear response and stability of the varistor [4]. It is essential to obtain information on the optical absorption behavior of the ceramic ZnO doped with metal oxides for the examination of electronic states. The optical absorption behavior of ZnO doped with MnO2, Co3O4 is discussed for the different doping levels of V2O5 at different processing conditions
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
