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Bi3.15Nd0.85Ti3O12 (BNT) ferroelectric thin film was fabricated on Pt(111)/Ti/SiO2/Si substrate using pulsed laser deposition. Domain structure, domain switching and hysteresis loops of the BNT film were investigated via piezoresponse force microscopy (PFM). Clear domain structure, complete domain switching and strong piezoresponse are found in BNT film. The PFM images before and after poling illustrate that domain structure and domain switching are restricted by grain boundaries. The shifted P-V hysteresis loops and butterfly loops indicate that internal field exists in the prepared BNT film. Both grain boundaries and internal field affect domain switching of the polycrystalline BNT film. [ABSTRACT FROM AUTHOR]

The temperature dependences of the polarization switching properties of Bi3.15Nd0.85Ti3O12 (BNT) ferroelectric thin film in the range from 25 to 150°C have been investigated. With increasing temperature, the switchable polarization and switching time decrease. Meanwhile, the depolarization field due to the interfacial layer between the electrode and the BNT film increases with increasing temperature, which induces more domain back-switching. In addition, the local switching properties of BNT film have been studied using piezoresponse force microscopy, and it is found that the prepared BNT film has good local switching behaviors. [ABSTRACT FROM AUTHOR]

The effects of misfit strain on the electrocaloric (EC) properties of BaTiO3 thin films arestudied by using the Landau-Devonshire thermodynamic theory. The 'misfit-strain temperature' phase diagrams for different electric fields are constructed. It was found that the EC effect of a BaTiO3 thin film is strongly dependent on misfit strain. More interestingly, we found that BaTiO3 thin films with tensile misfit strain exhibit a sizable EC effect in a wider temperature range in comparison with those with compressive misfit strain. [ABSTRACT FROM AUTHOR]

The metal-ferroelectric-insulator-semiconductor (MFIS) structure diodes with SrBi2Ta2O9 (SBT) as ferroelectric thin film and HfO2 as insulating buffer layer were fabricated. The electrical properties of MFIS structure were investigated for different HfO2 buffer layer thickness. The experimental results show that the memory window extended significantly as the HfO2 layer thickness increased from 6 to 10 nm. It is also observed that the leakage current was reduced to about 10-10 A at applied voltage of 4 V, and the high and low capacitances remained distinguishable for over 8 h even if we extrapolate the measured data to 10 years. [ABSTRACT FROM AUTHOR]

Despite the importance of interface dipole on the charge carrier injection at metal/organic contacts, there is yet no estimation of the various contributions to the overall dipole. We propose a simple approach to delineate and estimate the contribution of metal-induced interface states (MISs) toward the overall dipole. The relative contribution of the MIS was found to increase as the slope parameter decreases. By using published results, we estimate the relative MIS contributions in organic-silver contacts for various organic semiconductors to be -30%–80% of the overall dipole. [ABSTRACT FROM AUTHOR]

Thin films of Nd3+/Zr4+ cosubstituted Bi4Ti3O12 (BIT), i.e., Bi3.15Nd0.85Ti2.8Zr0.2O12 (BNTZ), were fabricated on Pt/Ti/SiO2/Si(100) substrates by chemical solution deposition and annealed at different temperatures of 600, 650, 700, and 800 °C. The effects of annealing temperature on the microstructure, leakage current, ferroelectric, and dielectric properties of the BNTZ films were investigated in detail. Significantly, compared with the Bi3.15Nd0.85Ti3O12 film, the BNTZ thin film has a lower coercive field (2Ec) and leakage current density and a slightly larger remnant polarization (2Pr). It shows that Nd3+/Zr4+ cosubstitution in BIT film might be an effective way to improve ferroelectric properties of BIT. [ABSTRACT FROM AUTHOR]

Metal-induced photoluminescence (PL) quenching of organic thin film [tri-(8-hydroxyquinoline) aluminum (Alq)] has been investigated both experimentally and theoretically. By doing experiments in situ in high vacuum, we have measured the PL intensity of Alq film deposited on metal-doped Alq film or metal film as a function of its thickness. For the case of metal-doped Alq film, exciton diffusion length of Alq is derived as LD=8.6±0.1 nm by analyzing experimental results and using a model based on diffusion and interface dissociation of excitons. For the case of metal film, another model considering exciton diffusion, interface dissociation, and nonradiative energy transfer to the metal is suggested to explain the experimental observation. Good agreement is achieved between theory and experiment. [ABSTRACT FROM AUTHOR]