On the electronic improvement of multi-crystalline silicon via gettering and hydrogénation

The electronic properties of multi-crystalline silicon must be improved during solar cell fabrication if highly efficient devices are to be made. This work shows how gettering and silicon nitride induced hydrogénation improve three properties: carrier lifetime, interstitial iron concentration, and trap density. Area averaged effective carrier lifetimes less than 10 μs were improved to greater than 60 μs. A tenfold reduction in trap densities was achieved. Photoluminescence images showing the influence processing techniques have on the electronic properties of the silicon are presented.