It is shown for the first time that sequential plasma-enhanced chemical vapor deposition (PECVD) of SiN and SiO2 can produce a very effective double-layer antireflection (AR) coating. This AR coating is compared with the frequently used and highly efficient MgF2/ZnS double layer coating. It is shown that the SiO2/SiN coating improves the short-circuit current (J(sc)) by 47%, open-circuit voltage (V(oc)) by 3.7%, and efficiency (Eff) by 55% for silicon cells with oxide surface passivation. The counterpart MgF2/ZnS coating gives similar but slightly smaller improvement in V(oc) and Eff. However, if silicon cells do not have the oxide passivation, the PECVD SiO2/SiN gives much greater improvement in the cell parameters, 57% in J(sc), 8% in V(oc), and 66% in efficiency, compared to the MgF2/ZnS coating which improves J(sc) by 50%, V(oc) by 2%, and cell efficiency by 54%. This significant additional improvement results from the PECVD deposition-induced surface/defect passivation. The internal quantum efficiency (IQE) measurements showed that the PECVD SiO2/SiN coating absorbs fair amount of photons in the short-wavelength range (< 500 nm), however, the improved surface/defect passivation more than compensates for the loss in J(sc) and gives higher improvement in the cell efficiency compared to the MgF2/ZnS coating.
