Effect of thickness on dielectric, ferroelectric, and optical properties of Ni substituted Pb(Zr0.2Ti0.8)O3 thin films
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We report thickness dependent dielectric,ferroelectric, and optical properties of Ni substituted Pb(Zr0.2Ti0.8)O3 thin films. The Pb(Zr0.2Ti0.8)0.70Ni0.30O3−δ (PZTNi30) thin films for various thicknesses, ranging from 5 nm to 400 nm, were fabricated by pulsed laser deposition technique. Giant dielectric dispersion, low dielectric loss, large dielectric constant -1000–1500 from 100 Hz to 100 kHz, and diffused dielectric anomaly near 570–630 K were observed in PZTNi30 thin films. These films show well saturated ferroelectric hysteresis, with large remanent polarization. It also illustrated excellent optical transparency which decreased from 82 to 72% with increasing film thickness from 5 nm to 400 nm for the probe wavelengths ranging from 200 to 1100 nm. A decrease in direct bandgap (Eg) values from 4 eV to 3.4 eV and indirect-Eg values from 3.5 eV to 2.9 eV were observed for PZTNi30 thin films with increase in film thickness from 5 nm to 400 nm, respectively. The direct and indirect bandgaps were discussed in context of film thickness and grain size effects. Our investigations on optical properties of PZTNi30 thin films suggest that bandgap can be modified as a function of film thickness which may be useful for readers working to develop novel candidates for ferroelectric photovoltaic.
Kumari , S , Ortega , N , Pradhan , D K , Kumar , A , Scott , J F & Katiyar , R S 2015 , ' Effect of thickness on dielectric, ferroelectric, and optical properties of Ni substituted Pb(Zr 0.2 Ti 0.8 )O 3 thin films ' Journal of Applied Physics , vol 118 , no. 18 , 184103 . DOI: 10.1063/1.4935481
Journal of Applied Physics
© 2015 AIP Publishing LLC. This work is made available online in accordance with the publisher’s policies. This is the final published version of the work, which was originally published at: https://dx.doi.org/10.1063/1.4935481
This work was supported by NSF Grant EPS-01002410. N. Ortega acknowledges support from the DoE Grant DE-FG02-08ER46526.