Innovative emitter design for low-cost silicon based heterostructure solar cells

N+ transparent conductor oxides (TCO's) can be a valuable and low-cost alternative to conventional thermally diffused emitter of silicon based solar cells. With reduced resistivities by appropriate doping and considering lattice mismatch and energy band offsets at the interface with p-silicon substrate, predictive study by numerical simulation shows comparable performance between ZnS:Al and TiO2:Nb with conversion efficiencies >16%. Furthermore, a back surface field achieved by a thin Sb2Te3 can enhance the efficiency with values higher than 18.5%.