Light Trapping in Bifacial Solar Modules Using Effectively Transparent Contacts (ETCs)

We have performed a computational study on the enhancement of the light absorption within bifacial solar modules with effectively transparent contacts (ETCs). ETCs are triangular cross-section silver fingers that redirect light to the active area of the solar cell and therefore, mitigate finger grid shading losses. Furthermore, ETCs can be spaced densely leading to light trapping. We used a combination of thin film and ray optical simulations and determined that light absorption can be increased by more than 4.5% compared to state-of-the-art metallization due to light trapping and effective transparency. Furthermore, we calculated that grid resistance and silver usage can be improved when using ETCs.