Solar cell
Discussed is a solar cell includes a semiconductor substrate, a conductive type region including a first conductive type region and a second conductive type region formed on one surface of the semiconductor substrate, an electrode including a first electrode and a second electrode, wherein the first electrode is connected to the first conductive type region and the second electrode is connected to the second conductive type region, and a passivation layer formed on the conductive type region. The passivation layer includes at least one of silicon nitride and silicon carbide.
1. A solar cell, comprising:
a semiconductor substrate including single-crystalline silicon;
a conductive type region comprising a first conductive type region and a second conductive type region formed on a back surface of the semiconductor substrate, the conductive type region including a polycrystalline silicon layer;
a first passivation layer comprising a silicon nitride layer formed on the conductive type region, and a silicon carbide layer formed on the silicon nitride layer;
an electrode comprising a first electrode and a second electrode, wherein the first electrode of a metal electrode being in contact with the polycrystalline silicon layer constituting the first conductive type region through a first opening penetrating the silicon nitride layer and the silicon carbide layer and the second electrode of a metal electrode being in contact with the polycrystalline silicon layer constituting the second conductive type region through a second opening penetrating the silicon nitride layer and the silicon carbide layer; and
an anti-reflection layer including silicon nitride on a front surface of the semiconductor substrate,
wherein a refractive index of the silicon nitride layer is larger than a refractive index of the anti-reflection layer.
2. The solar cell according to claim 1 , wherein the refractive index of the silicon nitride layer is larger than a refractive index of the silicon carbide layer.
3. The solar cell according to claim 1 , wherein the silicon nitride layer has a thickness that is the same as or larger than a thickness of the silicon carbide layer.
4. The solar cell according to claim 3 , wherein a ratio of the thickness of the silicon carbide layer: the thickness of the silicon nitride layer is about 1:1 to about 1:4.
5. The solar cell according to claim 1 , wherein the silicon nitride layer has a thickness of about 50 nm to about 200 nm.
6. The solar cell according to claim 1 , wherein the silicon carbide layer has a thickness of about 10 nm to about 50 nm.
7. The solar cell according to claim 1 , further comprising a second passivation layer between the semiconductor substrate and the anti-reflection layer.
8. The solar cell according to claim 1 , wherein the silicon carbide layer has a refractive index of about 1.5 to about 2.0.
9. The solar cell according to claim 1 , wherein at least one of the first electrode and the second electrode comprises a plurality of metal layers formed by sputtering.
10. The solar cell according to claim 1 , further comprising a tunneling layer between the back surface of the semiconductor substrate and the conductive type region.