J. Muto

Bio: J. Muto is an academic researcher from Keio University. The author has contributed to research in topics: Electrochromism & Phthalocyanine. The author has an hindex of 5, co-authored 5 publications receiving 38 citations.

Chalcopyrite thin film solar cells by electrodeposition

Abstract: This paper reviews the state of the art in using electrodeposition to prepare chalcopyrite absorber layers in thin film solar cells. Most of the studies deal with the direct preparation of Cu(In,Ga)Se 2 films, and show that the introduction of gallium in the films is now becoming possible from single bath containing all the elements. Electrodeposition can also be used to form precursor films with stacked layer structures, of pure elements or of combinations with binary or even ternary films. Thermal annealing treatments are of dramatic importance to provide suitable electronic quality to the layers. They are often done in the presence of a chalcogen (selenium or sulfur) over pressure and there is a tendency to use rapid thermal processes. Less studies are devoted to complete solar cell formation. Significant progresses have been made in the recent period with several groups achieving cell efficiencies around 8–10% on different substrates. A record efficiency of 11.3% is reported for a cell with an absorber presenting a band gap of 1.47 eV. First results on the manufacturability of the corresponding process to large areas are presented.

Interpretation of the Near-Infrared Absorption of Magnesium Phthalocyanine Complexes in Terms of Exciton Coupling Effects

Abstract: Magnesium phthalocyanine (MgPc) is a blue pigment whose X-phase is known to exhibit an intense near-IR-absorption. Because of this, MgPc has attracted attention as a material useful for laser print...

Electrodeposition and Growth Mechanism of Copper Sulfide Nanowires

Abstract: Thiourea (TU) is widely used as a corrosion inhibitor or as an additive in metal (e.g., copper) electroplating baths. TU facilitates the formation of uniform deposits with high brightness. In this ...

Synthesis, crystal structure and characterisation of aquamagnesium phthalocyanine—MgPc(H2O). The origin of an intense near-IR absorption of magnesium phthalocyanine known as ‘X-phase’

Abstract: The crystals of a triclinic modification of MgPc(H 2 O) were obtained by dissolving MgPc in benzonitrile with a small amount of water and slow recrystallization at about 80 °C. In the crystal there are two independent MgPc(H 2 O) molecules in the asymmetric unit. The independent molecules are very similar, the 4+1 coordinated central magnesium atom is significantly displaced from the N 4 -isoindole plane of the distorted Pc rings (∼0.45 A) toward the oxygen atom of coordinated water molecules. The geometry of the MgPc(H 2 O) molecule in the crystal ( C 1 -symmetry) is compared with the ab initio full-optimised geometry ( C 4 v ) that corresponds to the conformation of the molecule in solution. In contrast to the monoclinic modification of MgPc(H 2 O), which is not near-IR active, this triclinic modification shows an intense broad absorption band in this spectral region that is very similar to that observed in the solid state spectrum of β-MgPc. The near-IR absorption is characteristic only for the solid state samples since the spectra of MgPc(H 2 O) and β-MgPc in pyridine solution are similar and show only one intense Q band with characteristic splitting due to the vibronic coupling in the excited state. The intense absorption band observed in the spectrum of solid state of MgPc(H 2 O) as well as in the spectrum of β-MgPc originates from the arrangement of the molecules in dimers with strong π–π interactions between the distorted Pc macrorings. The molecular distortion (reduction in the symmetry C 4 v → C 1 ) lifts the double degeneracy of the excited state.

Heat treatment effect on the single oscillator parameters and optical band gap of an organic thin film

Abstract: The effect of heat treatment on the optical band gap and refractive index dispersion of 2,9,16,23-tetraneopentoxyphthalocyaninato zinc(II) thin film has been investigated. The absorption edge with increasing annealing temperature was shifted to the lower energy side and fundamental absorption edge is formed by a direct allowed transition. The refractive index and dispersion parameters E o and E d of the thin film were determined. The obtained results show that the film is suitable to change refractive index and oscillator parameters by heat treatment.