Teruhisa Kanbara

Photo-rechargeable solid state battery

Photoelectrochemical reactions on a semiconductor electrode (P-I aSi/SiO x ) with a silver ion conductive solid electrolyte (Ag 6 I 4 WO 4 ) have been investigated and photo-sensitizing effect was observed. On the basis of this reaction, photo-battery was examined which had a capability of self-charging under the sun or fluorescence illuminations. The battery consist of two parts. One is a MIS-type photovoltaic part (ITO/P-I as aSi/SiO x /Ag), and another is its energy storage part (Ag x V 2 O 5 /Ag 6 WO 4 /Ag x− V 2 O 5 ). Behaviors of photo reactions and the electrochemical characteristics in this system are discussed

Rechargeable solid-state batteries with silver ion conductors

Abstract Electrochemical behaviors of silver vanadium bronzes (Ag x V 2 O 5 ) with silver ion conductor (Ag 6 I 4 WO 4 ) were investigated in 0.3≦ x ≦1.0. Coulometric titration curves of these bronzes indicated that δ-phase bronze was available as electrode materials in solid-state cells using silver ion conductors. Properties of the rechargeable solid-state battery system (Ag 0.7 V 2 O 5 /Ag 6 I 4 WO 4 / Ag 0.7 V 2 O 5 ) were examined, and this battery showed excellent reversibility, stability, and shelf life in open-air and at high temperature.

A new type of amorphous silicon solar cell with high thermal stability

A new type of solar cell has been developed with hydrogenated amorphous silicon (a-Si:H). The cell structure is glass/ITO/(P-a-Si:H)/(I-a-Si:H)/(SiOx-complexes)/(Al+O-complexes). In comparison with a conventional PIN-type a-Si solar cell glass/ITO/(P-a-Si:H)/(I-a-Si:H)/(N-a-Si:H)/Al, the new-type cell gives much higher stability against thermal degradation which is caused by internal diffusion of Si and Al at the interface of the back-side electrode on the solar cell. The conversion efficiency of the conventional cell decreased from 6% to less than 1%, but the new-type cell maintained the same efficiency of 5.2% (AM1, 100 mW/cm2) after the storage at 120°C for 20 days. The new-type cell has the open circuit voltage Voc=0.86 (V), short-circuit current Jsc=12 mA/cm2, and fill factor ff.=0.50, yielding conversion efficiency of η=5.2% under AM1.0 of 100 mW/cm2, and Voc=0.62 (V), Jsc=18 µA/cm2, ff.=0.73 under a white fluorescent lamp of 200 lx. These photovoltaic parameters are almost the same as those of conventional PIN-type a-Si solar cells. In this paper, fabrication and photovoltaic performance of the thermal stability of the new-type cell are discussed in comparison with conventional solar cells.