Hole conducting, optically transparent Cu2O thin films on glass substrates have been synthesized by vacuum annealing (5×10−6 mbar at 700 K for 1 hour) of magnetron sputtered (at 300 K) CuO thin films. The Cu2O thin films are p-type and show enhanced properties: grain size (54.7 nm), optical transmission 72% (at 600 nm) and Hall mobility 51 cm2/Vs. The bulk and surface Valence band spectra of Cu2O and CuO thin films are studied by temperature dependent Hall effect and Ultra violet photo electron Spectroscopy (UPS). CuO thin films show a significant band bending downwards (due to higher hole concentration) than Cu2O thin films.

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The tailoring and understanding of the metal-insulator transitions (MITs) in vanadium sesquioxide, V2O3, is of major interest for both applications and fundamental physics. V2O3 has been characterized by MIT and concurrent structural transition at ∼155 K; however, the nature of the MIT has remained more elusive. We investigated the MIT and the electronic structure (in metallic phase) of the pulsed laser deposition grown strained vanadium sesquioxide thin films on Si. The strained thin films synthesized here show the suppression (by ∼23 K) of the MIT to lower temperatures, whilst the structural transition temperature decreases only by ∼10 K. Our results systematically confirm that albeit the structural changes are crucial in V2O3, electronic transition seems to be of Mott-Hubbard type. Stabilization of the metallic phase in the strained V2O3 thin film has been manifested from resistivity data and observations of the increased crystal field and quasiparticle features.

We investigate the resistive switching behavior of Ba-doped BiFeO3 (BBFO) films grown on single crystalline SrTi0.99Nb0.01O3 substrates. Observation of diode like I-V behavior and reduction in VC with Ba-content in BBFO films have been understood in the context of modifications in its energy band diagram. Also, I-V curves exhibit hysteresis which has been explained on the basis of migration and recombination of oxygen vacancies under field conditions. Furthermore, increment in Ba-content improves the retention property and ON/OFF switching ratio in BFO films which makes them suitable for applications in switching devices.

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