This study reports the fabrication of highly efficient heterojunction back contact (HBC) solar cells with a certified efficiency of 27.09% using a laser patterning technique. Recombination losses are primarily attributed to the hole-selective contact region and polarity boundaries. Solutions are proposed, and a relationship between contact resistivity, series resistance, and rear-side pattern design is established. Wafer edge recombination is identified as a significant current density loss channel. Further efficiency improvements up to 27.7% are projected with advanced passivation and optical enhancements.
