Efficient red electroluminescence from the excimer or oligomer of neutral phosphorescent bis(pyrrole)-diimine Pt(II) complex has been achieved with maximum external quantum efficiency, luminous efficiency, power efficiency and brightness of 6.5%, 9.0 cd A⁻¹, 4.0 lm W⁻¹ and 11 100 cd m⁻², respectively.

Magnetic particle imaging (MPI) is a promising medical imaging technique producing quantitative images of the distribution of tracer materials (superparamagnetic nanoparticles) without interference from the anatomical background of the imaging objects (either phantoms or lab animals). Theoretically, the MPI platform can image with relatively high temporal and spatial resolution and sensitivity. In practice, the quality of the MPI images hinges on both the applied magnetic field and the properties of the tracer nanoparticles. Langevin theory can model the performance of superparamagnetic nanoparticles and predict the crucial influence of nanoparticle core size on the MPI signal. In addition, the core size distribution, anisotropy of the magnetic core and surface modification of the superparamagnetic nanoparticles also determine the spatial resolution and sensitivity of the MPI images. As a result, through rational design of superparamagnetic nanoparticles, the performance of MPI could be effectively optimized. In this review, the performance of superparamagnetic nanoparticles in MPI is investigated. Rational synthesis and modification of superparamagnetic nanoparticles are discussed and summarized. The potential medical application areas for MPI, including cardiovascular system, oncology, stem cell tracking and immune related imaging are also analyzed and forecasted.

An accurate and sensitive method is reported to measure the thin-film density of vacuum-deposited, small-molecular organic semiconductor materials. A spectrophotometer and surface profiler had been used to determine the mass and thickness of organic thin film, respectively. The calculated density of tris-(8-hydroxyquinolato) aluminum $\left({\text{Alq}}_3\right)$ thin film was $1.31\pm 0.01\text{g}∕{\text{cm}}^3$ . Vacuum pressures and thin-film growth rates are found to have less impact on the thin-film density of organic material. However, the thin-film density of organic material strongly depends on its chemical structure and molecular weight. Specifically, the chemical structure determines the density of organic material that affects the molecular volume and intermolecular stacking.

This paper reviews the studies on La-based high-k dielectrics for metal-oxide-semiconductor (MOS) applications in recent years. According to the analyses of the physical and chemical characteristics of La₂O₃, its hygroscopicity and defects (oxygen vacancies, oxygen interstitials, interface states, and grain boundary states) are the main problems for high-performance devices. Reports show that post-deposition treatments (high temperature, laser), nitrogen incorporation and doping by other high-k material are capable of solving these problems. On the other hand, doping La into other high-k oxides can effectively passivate their oxygen vacancies and improve the threshold voltages of relevant MOS devices, thus improving the device performance. Investigations on MOS devices including non-volatile memory, MOS field-effect transistor, thin-film transistor, and novel devices (FinFET and nanowire-based transistor) suggest that La-based high-k dielectrics have high potential to fulfill the high-performance requirements in future MOS applications.

The effects of Ta incorporation in La₂O₃ gate dielectric of amorphous InGaZnO thin-film transistor are investigated. Since the Ta incorporation is found to effectively enhance the moisture resistance of the La₂O₃ film and thus suppress the formation of La(OH)₃, both the dielectric roughness and trap density at/near the InGaZnO/dielectric interface can be reduced, resulting in a significant improvement in the electrical characteristics of transistor. Among the samples with different Ta contents, the one with a Ta/(Ta + La) atomic ratio of 21.7% exhibits the best performance, including high saturation carrier mobility of 23.4 cm²/V·s, small subthreshold swing of 0.177 V/dec, and negligible hysteresis. Nevertheless, excessive incorporation of Ta can degrade the device characteristics due to newly generated Ta-related traps.