Toshio Yamashita

Screen printed thin film CdS/CdTe solar cell.

Thin film CdS/CdTe solar cells with an efficiency of 6.3 % have been prepared on a borosilicate glass substrate of 4s×4 cm2 by successively repeating screen printing and heating (sintering) of each paste of CdS, CdTe and C. The CdS paste consists of CdS, CdCl2, GaCl2 and propylene glycol (PG). The CdTe paste contains CdCl2 and PG, and the C paste contains PG and a small amount of acceptor impurity. During the heating of C paste, an nCdS/pCdTe heterojunction is formed. In the most efficient cell, the peak of electron voltaic effect exists within 1 µm of the CdTe side from the CdS/CdTe metallurgical boundary. The C electrode cell is more stable than the previous Cu2Te electrode cell for an accelerated life test. From 25 elemental cells with 4×4 cm2 substrate, a 1 watt module has tentatively been constructed with a module efficiency of 2.9 %.

A 2048-element contact-type linear image sensor for facsimile

In order to realize more compact facsimile equipment, a contact type linear image sensor has been developed. The imager has the same length as the document width and does not require an optical lens system, as the imager virtually contacts the document. A new fabrication process, which combines CdS chemical bath deposition and CdSe vapor deposition, is adopted for photoconductive thin film. The process condition for CdS-CdSe mixing ratio is established to most suitably satisfy facsimile application characteristics, such as spectral response and photo response speed. By paying particular consideration to such structure design as the sensing aperture and scanning circuit, trial 2048-element, 256 mm long imager was successfully fabricated. Evaluation of the trially fabricated imager and its photo-electric conversion unit showed excellent operational properties and utilization for facsimile equipment.