Investigating the Impact of Cracks on Solar Cells Performance: Analysis Based on Nonuniform and Uniform Crack Distributions
Mahmoud Dhimish, Vincenzo d’Alessandro, Santolo Daliento
Abstract
The article investigates the detrimental effect of nonuniform and uniform crack distributions over a solar cell in terms of open-circuit voltage ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">${{\bm{V}}_{{{\bf oc}}}}$</tex-math></inline-formula> ), short-circuit current density ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">${{\bm{J}}_{{{\bf sc}}}}$</tex-math></inline-formula> ), and output power, the latter under a wide range of irradiance conditions. The experimental procedure to detect the cracks relies on electroluminescence (EL) imaging, which is nondestructive and requires a relatively low amount of time. The Griddler software is adopted to translate the EL-taken image into <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">${{\bm{V}}_{{{\bf oc}}}}$</tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">${{\bm{J}}_{{{\bf sc}}}}$</tex-math></inline-formula> maps. The main findings can be summarized as follows: the nonuniformly and uniformly cracked cells are both jeopardized in terms of output power; the loss corresponding to the cell with nonuniform distribution of cracks is increasingly higher than the uniformly cracked counterpart as the irradiance hitting the cells grows; and all cells affected by nonuniform cracks are severely damaged in terms of fingers and rear busbar, which concur to limit the maximum output current.