Efficient Black Silicon Photovoltaic Devices With Enhanced Blue Response

A photovoltaic device, comprising:

• a silicon wafer with a back surface and a front, light-receiving surface;
• a layer of black silicon, on the front, light-receiving surface, comprising a plurality of nanostructures with lateral structure dimensions greater than 65 nanometers;
• and
• an emitter comprising dopant diffused a depth into the front, light-receiving surface through and beyond the layer of the black silicon, wherein a maximum level of the dopant is less than about 3×1021 cm−3.

A method of fabricating photovoltaic devices, comprising:

• forming black silicon on a surface of a silicon substrate;
• forming an emitter in the silicon substrate by diffusing a dopant into the black silicon surface;
• processing the silicon substrate to remove an outer layer of the black silicon surface to remove a volume of highly doped silicon;
• forming a surface passivation coating on the black silicon surface;
• and
• attaching front and back electrical contacts to the silicon substrate.

A method of making a photovoltaic device, comprising:

• forming a black silicon layer comprising nanostructures on a surface of a silicon substrate;
• processing the surface of the silicon substrate to remove an outer portion of the black silicon layer to increase the lateral structure dimensions of the nanostructures;
• forming an emitter in the silicon substrate by diffusing a dopant into the black silicon layer;
• and
• forming a surface passivation coating on the black silicon layer.

A method of fabricating a photovoltaic device, comprising:

• forming black silicon on a surface of a silicon wafer;
• and
• forming an emitter in the surface of the silicon wafer including diffusing a dopant into the black silicon,
• wherein the forming of the black silicon includes increasing average lateral structure dimensions of nanostructures in the black silicon to a range of 65 to 200 nanometers, and
• wherein the emitter has a dopant level providing a sheet resistance of at least about 90 ohm/sq.