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.

Assessment of 3D micro-computed tomography for PV interconnection technology development

“…Previous publications reported on a multi-ribbon interconnection for back-contact solar cells based on a 3D woven fabric of interconnection ribbons in an encapsulant matrix [19]. Reliability tests on samplesized modules have shown the potential of this technology [20], but further tests on the fabrication processes are required to support the industrial development of the concept. Especially the solder joint formation is an essential aspect in evaluating its novel combined soldering and lamination approach.…”

“…The one-cell module is fabricated using a twostep process involving a lay-up and lamination phase [19]. It consists of 2 mm thick glass front-and backsheets, an encapsulant between the front sheet and the cells, and a 420 µm thick glass-fiber reinforced thermoplastic polyolefin encapsulant with integrated interconnection ribbons between the backside of the cell and the backsheet.…”

“…This work attempts to implement and further investigate how industrial μCT can benefit PV research with a module with three-dimensional multiribbon interconnection as an object of study [19]. A one-cell module was fabricated and electrically characterized using EL imaging and I-V characterization before, during, and after reliability testing.…”