Application of thick film techniques to the manufacture of solar cells

Abstract

Thick film technology offers advantages of low cost, production amenability and automation. Its use in hybrid circuit technology, where it offers added advantages of reliability and miniaturisation, is well known. The technology involves the screen printing of especially formulated pastes followed by firing at high temperatures. This technology has also been successful in the manufacture of silicon solar cells as well as in the development of complete silicon solar cells using CdS/CdTe heterojunctions. It enables the use of the same equipment in the various processes involved in manufacturing solar cells. This paper reviews the application of thick film techniques to the manufacture of solar cells. The thick film processing techniques are really attractive when used for diffusion of doping impurities, metallisation, wrap-round contacts, antireflection coatings and interconnections involved in the bonding, soldering and panelling of silicon solar cells. Attempts to make CdS/CdTe heterojunctions using thick film techniques on a different substrate have already met with some success, so that complete solar cells can be made on glass using low cost thick film processing techniques. This opens new methods of solar cell production which are cost competitive and economically viable.