Novel dual-layered passivation approach for 18.8% efficiency laser doped selective emitter cells

A new approach for performance improvement of laser doped selective emitter cells with dual dielectric passivation layers was demonstrated. Taking advantage of recovery of laser induced defects and emitter passivation of dual dielectric layer, a new scheme has been implemented to laser doped selective emitter cells. With this dual layer structure, it is shown that both of the lightly doped and laser treated areas get higher photoluminescence response and the open circuit voltage increases from 636mV to 640mV, compared to conventional single dielectric passivation layer. The slightly optical loss is a trade-off on this kind of dual-layered passivation due to non-optimum refraction match for light trapping, but this can be compensated by better internal quantum response. Laser doped selective emitter cells with dual-layered passivation scheme show 18.8% efficiency in average with 0.3%abs efficiency gain, compared to single layer passivated cells.