Heterojunction solar cell based on epitaxial crystalline-silicon thin film on metallurgical silicon substrate design

A heterojunction solar cell, comprising:

• a metallurgical-grade Si (MG-Si) substrate;
• a layer of heavily doped epitaxial mono-crystalline-Si situated above the MG-Si substrate, wherein the heavily doped epitaxial mono-crystalline-Si layer is in direct contact with the MG-Si substrate;
• a layer of lightly doped epitaxial mono-crystalline-Si situated above the heavily doped epitaxial mono-crystalline-Si layer;
• a backside ohmic-contact layer situated on the backside of the MG-Si substrate;
• a passivation layer situated above the heavily doped epitaxial mono-crystalline-Si layer;
• a layer of heavily doped amorphous Si (a-Si) situated above the passivation layer;
• a layer of transparent-conducting-oxide (TCO) situated above the heavily doped a-Si layer;
• and
• a front ohmic-contact electrode situated above the TCO layer.