Partially transmitted imaged laser beam for scribing solar cell structures

Provided herein are methods and systems for scribing solar cell structures to create isolated solar cells. According to various embodiments, the methods involve scanning an excimer laser beam along a scribe line of a solar cell structure to ablate electrically active layers of the structure. A photomask having variable transmittance is disposed between the beam source and the solar cell structure. The transmittance is calibrated to produce variable fluence levels such that a stepped scribed profile is obtained. In certain embodiments, a front contact/absorber/back contact stack is removed along a portion of the scribe line, while a front contact/absorber stack is simultaneously removed along a parallel portion, with the back contact layer unremoved. In this manner, the scribe electrically isolates solar cells on either side of the scribe line, while providing a contact point to the back contact layer of one of the solar cells for subsequent cell-cell interconnection.