Room temperature electrical properties of Bi0.7Dy0.3FeO3 thin films deposited by PLD on ZnO films for potential applications

The Electrical properties of Bi0.7Dy0.3FeO3 (BDFO) thin films deposited by pulsed laser deposition (PLD) on ZnO/Si films and its potential applications are discussed in this paper. MIS (metal/insulator/semiconductor) Capacitors of Cr-Au/BDFO/ZnO/p-Si structures have been fabricated and their interface traps and electrical properties have been investigated. To obtain the information about the interface trap states, systematic studies on the frequency-dependent capacitances and conductance measurement were performed. Frequency dependent analysis of the device was made in the frequency range of 10 kHz-500 kHz. It was observed that dispersion of the oxide capacitance was 2% per decade within this frequency range. When the sweeping voltage changes from -3 to +4 V the memory aperture was found to be increased from 300 to 850 mV. This significant hysteresis property in the C-V characteristics may be attributed to the slight ferroelectric behaviour of BDFO/ZnO film, which is essential for a memory device. It was also observed that density of trap state (D-it) is found approximately. 9 x 10(11) cm(-2) eV(-1) while increasing the frequency from 10 kHz to 500 kHz, the thickness of the oxide layer was 300 nm in this experiment. The calculated dielectric constant of device (similar to 190) is much higher than that of BDFO (>30). The dielectric loss tangent of the device was found to initially increase with voltage then decrease, whereas the ac conductivity depicted an opposite trend. Multiferroic BDFO is promising material shows the good coupling between ferroelectric and ferromagnetic properties and ideal behaviour at room temperature. Integration of BDFO films with ZnO piezoelectric can be used directly as electricity generator with enhanced output in MEMS applications as well as in Memory devices. (C) 2016 Elsevier B.V. All rights reserved.