Solar cell having silicon nano-particle emitter
View Patent ↗A silicon solar cell having a silicon substrate includes p-type and n-type emitters on a surface of the substrate, the emitters being doped nano-particles of silicon. To reduce high interface recombination at the substrate surface, the nano-particle emitters are preferably formed over a thin interfacial tunnel oxide layer on the surface of the substrate.
1. A method of fabricating a silicon solar cell having nano-particle silicon emitters comprising the steps of:
providing a silicon substrate having first and second opposing major surfaces;
forming a thin interfacial passivation layer on one of the first and second opposing major surfaces, wherein forming the thin interfacial passivation layer comprises forming a tunnel oxide layer;
forming a first plurality of p-doped emitters formed using silicon nano-particles and a second plurality of n-doped emitters formed using silicon nano-particles, wherein at least one of the first plurality of p-doped emitters or the second plurality of n-doped emitters is formed on the thin interfacial passivation layer; and
forming first and second interconnect lines to the first plurality of p-doped emitters and to the second plurality of n-doped emitters, respectively.
2. The method of claim 1 further comprising:
applying a surfactant along with silicon nano-particles used to form the at least one of the first plurality of p-doped emitters or the second plurality of n-doped emitters on the tunnel oxide layer.
3. The method of claim 2 further comprising:
depositing a layer of undoped silicon nano-particles over the tunnel oxide layer and then selectively doping the layer of undoped silicon nano-particles to form the at least one of the first plurality of p-doped emitters or the second plurality of n-doped emitters.
4. The method of claim 1 further comprising:
providing surfactant in a solution with silicon nano-particles used to form the first plurality of p-doped emitters and the second plurality of n-doped emitters prior to forming the first plurality of p-doped emitters and the second plurality of n-doped emitters.
5. The method of claim 4 further comprising:
doping the silicon nano-particles used to form the first plurality of p-doped emitters and the second plurality of n-doped emitters prior to forming the first plurality of p-doped emitters and the second plurality of n-doped emitters.
6. The method of claim 5 further comprising:
inkjet printing of the first plurality of p-doped emitters and the second plurality of n-doped emitters.
7. The method of claim 5 further comprising:
screen processing to form the first plurality of p-doped emitters and the second plurality of n-doped emitters.
8. The method of claim 1 further comprising:
depositing a layer of undoped silicon nano-particles over the thin interfacial passivation layer and then selectively doping the layer of undoped silicon nano-particles to form the at least one of the first plurality of p-doped emitters or the second plurality of n-doped emitters.