Three-dimensional multi-ribbon interconnection for back-contact solar cells

Abstract

Back-contact solar cells are an interesting technology with advantages over traditional two-sided cells. A lack of standardized and low-cost interconnection methods inhibits their market penetration. In an attempt to overcome this obstacle, this work introduces an interconnection technology, based on a fabric of encapsulant with incorporated metal ribbons. The encapsulant is tailored for this application by adding glass fibres to a thermoplastic polyolefin. For this tailored encapsulant, characterization experiments were conducted and results on viscosity and coefficient of thermal expansion are shown. Initial reliability testing on sample-size modules with high-efficiency interdigitated back-contact (IBC) cells shows promising results, passing up to four times the IEC 61215 standard for thermal cycling.