The effect of an interface dipole layer on the energy level alignment at organic-conductor interfaces is studied on a copper phthalocyanine (CuPc) monolayer/electric dipole layer/graphite system via ultraviolet photoemission spectroscopy (UPS) and metastable atom electron spectroscopy. An oriented monolayer of the OTi-phthalocyanine molecule, which has an electric dipole moment, is grown on graphite to yield a welldefined dipole layer with the vacuum side negatively charged. The CuPc monolayer is sequentially deposited on the dipole layer kept at 123 K. This weakly interacting system made of a very thin organic layer on top of a very thin dipole layer is in thermodynamic equilibrium. The UPS data from the system grown with and without the interface dipole layer show that the binding energy of the highest occupied state of the CuPc monolayer decreases when the dipole layer is inserted. The binding energy shift is in excellent agreement with the increase in vacuum level energy of the graphite substrate upon deposition of the dipole layer. The results show that the Fermi level of the CuPc shifts toward the valence states when the interface dipole layer is inserted.

The effect of the molecular orientation on the molecular electronic structure is studied on the Cu-phthalocyanine∕graphite system via film thickness dependences of metastable-atom electron spectra and ultraviolet photoelectron spectra. We observed a decrease in the vacuum-level position and a corresponding band-bending-like shift in the highest occupied state only for thick films where the molecular tilt angle increases gradually with the film thickness. These shifts are explained by electric dipoles produced in the film by a gradient of the intermolecular electronic interaction along the surface normal due to the continuous increase in the molecular tilt angle. The result indicates that the change in the molecular orientation is an important origin of the band-bending-like shift in the molecular electronic states even if the molecule has no permanent electric dipole.

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The damage produced by focused ion beam (FIB) milling on a TEM sample of AlGaAs crystals has been studied. The damage observed on the sidewall of an AlGaAs transmission electron microscopy (TEM) sample was an amorphous layer. The thickness of the amorphous layer linearly increased with an increase in FIB accelerating voltage from 5 to 30 kV. The thickness of the amorphous layer of Al(x)Ga(1-x)As was constant at 3 nm and was independent of the Al concentration x when the accelerating voltage was below 5 kV. The thickness of the amorphous layer of Al(x)Ga(1-x)As decreased with an increase in Al concentration x when the accelerating voltage was above 5 kV. FIB milling at 5 kV effectively minimizes the thickness of the amorphous layer and also provides flat sidewalls on multilayer samples of Al(x)Ga(1-x)As that are prepared for TEM and scanning electron microscopy (SEM).

The molecular orientation of π‐conjugated polymers is a significant factor for the electrical properties of polymer‐based printable devices, because π‐conjugated polymers exhibit a notable fast carrier transport property along their main chain. Although various coating processes are suggested, the challenge to realize high‐degree alignment by one‐step coating without pre‐ or post‐treatments still remains. In this paper, it is reported on the fabrication of an extremely highly aligned thin film by a slow bar coating process using a donor–acceptor π‐conjugated polymer with great aggregability. The 2D order parameter achieved is 0.9, which is the highest obtained among the alignment methods with a one‐step coating process. Furthermore, the direction of the main chain is selectively oriented parallel or perpendicular to the coating direction depending on the solution concentration with high orientation degree. This unique orientation phenomenon seems to be related to the nematic liquid crystallinity of poly[2,5‐(2‐octyldodecyl)‐3,6‐diketopyrrolopyrrole‐alt‐5,5‐(2,5‐di(thien‐2‐yl)thieno [3,2‐b]thiophene)] aggregates formed by the slow coating process. The orientation dynamics is discussed by taking the structure and behavior of the aggregates in the solution into account.

It is important to understand the film formation mechanism of π-conjugated polymers to realize their high-performance electronic devices. In this study, the dynamics of the preaggregate, which affects the conformation and alignment of a typical donor−acceptor (D-A) π-conjugated polymer during film formation, was investigated by two approaches based on a smallangle X-ray scattering (SAXS) method. SAXS analysis of a highly concentrated solution, assuming the state before becoming the solid-state thin film, provided insight into the aggregation phenomena of the D-A π-conjugated polymer during the film formation process. In solution, the small rod-like structure of the polymer seems to form a large preaggregate, the shape of which almost coincided with that of the aggregate in the solid-state thin film. Besides, in situ grading incident SAXS (in situ GISAXS) analysis in the actual film formation process from the solution state revealed a microstructural change of the aggregate over time.

Fin field-effect transistors are promising next-generation electronic devices, and the identification of dopant positions is important for their accurate characterization. We report atom probe tomography (APT) of silicon fin structures prepared by a recently developed self-regulatory plasma doping (SRPD) technique. Trenches between fin-arrays were filled using a low-energy focused ion beam to directly deposit silicon, which allowed the analysis of dopant distribution by APT near the surface of an actual fin transistor exposed to air. We directly demonstrate that SRPD can achieve a boron concentration above 1 × 1020 atoms/cm3 at the fin sidewall.

Thin films of a typical organic–inorganic halide perovskite material, CH3NH3PbI3 (MAPbI3), were fabricated by a bar-coating method, which is one of the candidate techniques for large-scale production. The film thickness of MAPbI3 markedly changed depending on the sweep speed of the coating bar, that is, it decreased in evaporation regime under the low-speed condition, and increased in the Landau–Levich regime under the high-speed condition. The typical inverted-type p-i-n planar solar cells with the MAPbI3 thin films demonstrated the photoelectric conversion efficiency of 14.0%, and their photovoltaic properties depending on the sweep speed were discussed by taking the surface morphology and crystallinity into consideration.