Exploring morphological variation in bismuth ferrite nanostructures by pulsed laser deposition: synthesis, structural and electrochemical properties

Abstract

Structural and electrochemical properties of bismuth ferrite nanostructures produced by pulsed laser deposition with various morphologies are reported. The nanostructures are also explored as electrode materials for high-performance supercapacitors. Scanning electron microscopy images revealed that various bismuth ferrite morphologies were produced by varying the background pressure (10-6, 0.01, 0.10, 0.25, 0.50, 1.0, 2.0 and 4.0 Torr) in the deposition chamber and submitting them to a thermal treatment after deposition at 500 0C. The as-deposited bismuth ferrite nanostructures range from very compact thin-film (10-6, 0.01, 0.10 Torr), to clustered nanoparticles (0.25, 0.50, 1.0 Torr), to very dispersed arrangement of nanoparticles (2.0 and 4.0 Torr). The electrochemical characteristic of the electrodes was investigated through cyclic voltammetry process. The increase in the specific surface area of the nanostructures as background pressure in the chamber increases does not lead to an increase in interfacial capacitance. This is likely due to the weakening of electrical contact between nanoparticles with increasing porosity of the nanostructures. The thermal treatment increased the contact between nanoparticles, which caused an increase in the interfacial capacitance of the nanostructure deposited under high background pressure in the chamber.