Analysis of solar cells interconnected by electrically conductive adhesives for high-density photovoltaic modules

Interconnection of solar cells by an electrically conductive adhesive (ECA) can replace the use of conventional metal ribbon connections for photovoltaic module fabrication. This technology increases the active area for photocurrent generation because the cells are connected in a busbar-less structure, and high-power, high-efficiency modules can be manufactured. In this study, we investigated the influence of the curing conditions on the characteristics of the ECA film and interconnected cell. In addition, this paper presents a new method for extracting the resistance contribution of the ECA to the interconnected cell. A low sheet resistance of < 0.023 Omega/sq was observed when an ECA film on a slide glass substrate was cured for > 60 s, regardless of the curing temperature. In addition, the sheet resistance was < 0.02 Omega/sq at a curing temperature of 150 degrees C even for a short curing time of 5 s. At curing temperatures above 120 degrees C, the ECA resistance component of the interconnected cell was reduced to 0.2 m Omega or less, and the efficiency was increased by 0.4% or more. However, a curing time of > 60 s was required for a similar efficiency improvement at lower temperatures. Notably, the characteristics of the interconnected cell simulated using the extracted ECA resistance values were similar to the measurement results.