Phosphorus in-diffusion from a surface source by millisecond flash lamp annealing for shallow emitter solar cells

We have investigated in-diffusion of phosphorus into monocrystalline silicon by depositing a phosphorus source on the surface followed by millisecond flash lamp annealing (FLA) to form shallow emitters for solar cells. By varying both the energy density of a 20 ms flash in the range from 62 to 132 J/cm(2) and the sample preheating, it is observed that FLA treatments can in-diffuse a high concentration of phosphorus atoms becoming electrically active. The most promising emitters are obtained after FLA in the energy range from 110 to 128 J/cm(2) including preheating at 300 degrees C with a peak concentration of 4 - 6 x 10(20) cm(-3). The emitter junction depth for these treatments is in the range of 100 nm to 200 nm, respectively.