Influence of Technological Operation on PV Parameters of Edge-Illuminated Epitaxial Silicon Solar Cells

Abstract

The main goal of presented work is to state how the technological processes used to fabrication of edge–illuminated solar cells (EISC) affects cells parameters. The edge-illuminated PV cell is designed to cooperate with a luminescent solar concentrator (LSC). The unit cells in a shape of narrow strip were performed according to our concept from silicon epitaxial structures with p-n junction. The measurements of PV parameters of strips fabricated in the same technological conditions from silicon wafers with different multi-layers epitaxial structures allowed us to select the most suitable epitaxial structures for EISC application. The sequence of layers n+/n/p and p+/p/n deposited on highly doped p+ and n+ substrates has been chosen. PV stripe structures has been manufactured by thinning of Si wafer with epi-layers up to about 100 μm and next mechanical or laser cutting to final form of 40-80 mm long and 2 – 4 mm wide stripes. The Ni/Al contacts were deposited after thinning process. The effect of technological processing such as cutting process, chemical edge finishing and antireflection coating has been investigated. It was found that main affect on the PV cell parameters has chemical treatment of the edge surface, what indicates the important role of surface phenomena on the examined PV cells.