Impact of Microcracks on Performance of a Crystalline Silicon Photovoltaic Cell
Abstract
Solar cells are susceptible to the formation of microcracks throughout different stages of their lifespan. Microcracks can lead to power loss through different impacting mechanisms, such as enhancing surface recombination or increasing resistive losses, leading to performance loss in solar cells. These operating mechanisms can co-occur in a solar cell, which has yet to be studied in detail. In this work, the impact of different operating mechanisms of microcracks on the electrical performance of a solar cell has been analysed using PSpice simulations. Three scenarios have been considered to assess the effects of microcracks, namely, enhanced surface recombination mode, resistive loss mode, and a combination of both. Simulations have been performed using a distributed diode model of the solar cell for the three most occurring microcrack orientations. The results show that in resistive mode, the power loss is comparatively less for all microcrack orientations. For parallel to busbar microcrack, no resistive power loss is observed, and for diagonal and perpendicular to busbar microcrack, after a certain threshold resistance, the power loss does not increase due to changes in the path of the lateral current flow. The recombinative loss mode results in higher performance loss than the resistive loss mode. Further, depending on the presence of stress factors, performance loss due to a combination of both loss modes leads to higher performance loss, impacting its reliability. This work highlights the possible extent of performance loss due to the different operating mechanisms of microcracks.
Keywords
Microcracks, Recombinations, Resistive loss, Solar cell, Photovoltaics, Power loss