The potential efficiency of laser doped solar cells using photoluminescence imaging

In this work we evaluate the implied open circuit voltages (iVoc) at various stages of production of laser doped selective emitter (LDSE) solar cells using photoluminescence (PL) imaging The change of the iVoc values after the laser doping (LD) has shown that this process has minimal effect on cell performance. It is also found that the order of processes such as edge junction isolation and silicon nitride is of critical importance prior to light induced plating. If these processes are not performed in the correct order, localised shunts may form during the light induced plating (LIP) process which then inhibits plating near the edge of the cells. In this work, an impressive efficiency of 18.3% has been achieved, even though the fill factor was only 74.2% and the cell suffered from additional shading losses due to overplating. With the optimization of the LD and metallization processes cells have the potential to reach efficiencies of more than 19.2% on full size commercial substrates.