A novel silicon texturization method based on etching through a silicon nitride mask

We present a new texturing technique applicable to silicon solar cells. The technique is based on the isotropic etching of silicon through a very thin layer of silicon nitride, deposited by low-pressure chemical vapor deposition. Spectrophotometry measurements show that the resulting surface texture displays low reflectivity after encapsulation behind glass, and nearly ideal light-trapping behaviour. The surfaces can also be well passivated using standard passivation techniques. Emitter dark saturation currents in the range 4-5 × 10^-14 A/cm² have been measured by quasi-steady-state photoconductance following the growth of a thermal oxide.