Novel topcon cell structure and preparation method thereof

A preparation method for a solar cell structure comprising:

• providing a substrate comprising a front side and a back side;
• forming a first tunnel oxide layer on the front side of the substrate;
• depositing a first polycrystalline silicon layer on the first tunnel oxide layer;
• forming a second tunnel oxide layer on the back side of the substrate;
• depositing a second polycrystalline silicon layer on the second tunnel oxide layer;
• forming a first silicon nitride layer on the first polycrystalline silicon layer and a second silicon nitride layer on the second polycrystalline silicon layer;
• and
• forming a plurality of first electrodes on the first silicon nitride layer and a plurality of second electrodes on the second silicon nitride layer.