High efficiency n-type silicon solar cells featuring passivated contact to laser doped regions

Minimizing carrier recombination at cell contacts becomes increasingly important for reaching high efficiency. In this work, the passivated contact concept is implemented into n-type silicon solar cells with laser-processed local back surface fields. The passivation and contact characteristics of the SiO2/amorphous silicon (a-Si:H) stack on localized laser doped n+ regions are investigated. We find that the SiO2/a-Si:H stack provides not only good passivation to laser doped n+ regions but also allows a low contact resistivity after thermal annealing. With the implementation of the SiO2/a-Si:H passivated contact, an absolute efficiency gain of up to 1.5% is achieved for n-type solar cells.