Conductive paste and solar cell
A conductive paste and a solar cell. The conductive paste includes a conductive powder, a first glass frit, and a second glass frit. The first glass frit includes at least one of lead-containing glass and bismuth-containing glass. A glass transition temperature of the second glass frit is greater than 600° C. In the conductive paste, a weight percentage of the first glass frit ranges from 0.5% to 5%, and a weight percentage of the second glass frit ranges from 0.5% to 10%.
1 . A solar cell, comprising:
a semiconductor substrate;
an emitter arranged on a side of the semiconductor substrate;
a passivation layer group arranged on a side of the emitter away from the semiconductor substrate; and
a first electrode arranged on the side of the emitter away from the semiconductor substrate;
wherein the first electrode comprises a body portion and a plurality of connecting portions,
wherein the body portion extends through part of the passivation layer group; and the plurality of connecting portions are spaced apart on a side of the body portion adjacent to the emitter, and are in contact with the emitter.
2 . The solar cell of claim 1 ,
wherein the first electrode is made of a conductive paste electrically connected to the emitter; and
wherein the conductive paste comprises:
a conductive powder; and
a first glass frit comprising at least one of lead-containing glass and bismuth-containing glass.
3 . The solar cell according to claim 1 , wherein the passivation layer group comprises a first passivation layer, a first antireflection layer, and a second antireflection layer stacked in a direction away from the semiconductor substrate; silicon content of the second antireflection layer is less than that of the first antireflection layer;
the body portion extends through the second antireflection layer; and
the first antireflection layer comprises a first portion and a second portion, wherein an orthographic projection of the first portion on the semiconductor substrate does not overlap with an orthographic projection of the first electrode on the semiconductor substrate; the orthographic projection of the first electrode on the semiconductor substrate covers an orthographic projection of the second portion on the semiconductor substrate; and the second portion is provided between adjacent connecting portions.
4 . The solar cell according to claim 2 , wherein an area of orthographic projections of the plurality of connecting portions on the semiconductor substrate is a first area; and an area of the orthographic projection of the first electrode on the semiconductor substrate is a second area; and
a ratio of the first area to the second area ranges from 30% to 70%.
5 . The solar cell according to claim 2 , wherein the first electrode comprises first silver-containing particles and second silver-containing particles;
particle diameters of the first silver-containing particles are greater than or equal to 1 nm and less than or equal to 100 nm, and particle diameters of the second silver-containing particles are greater than 100 nm and less than or equal to 300 nm; and
part of the first silver-containing particles and part of the second silver-containing particles are in contact with the emitter.
6 . The solar cell according to claim 5 , wherein on a contact interface between the first electrode and the emitter, a quantity of particles of the first silver-containing particles is greater than a quantity of particles of the second silver-containing particles.
7 . The solar cell according to claim 6 , wherein on the contact interface between the first electrode and the emitter, the quantity of particles of the first silver-containing particles is a first value; a sum of the quantity of particles of the first silver-containing particles and the quantity of particles of the second silver-containing particles is a second value; and a ratio of the first value to the second value is no less than 80%;
wherein the conductive paste further comprises: a second glass frit having a glass transition temperature greater than 600° C.; wherein in the conductive paste, a weight percentage of the first glass frit ranges from 0.5% to 5%, and a weight percentage of the second glass frit ranges from 0.5% to 10%.
8 . The solar cell according to claim 2 , further comprising:
a tunnel layer arranged on a side of the semiconductor substrate away from the emitter;
a doped semiconductor layer arranged on a side of the tunnel layer away from the semiconductor substrate; and
a second electrode arranged on a side of the doped semiconductor layer away from the tunnel layer, and electrically connected to the doped semiconductor layer;
wherein a thickness of the doped semiconductor layer ranges from 5 nm to 80 nm.
9 . The solar cell according to claim 1 , wherein the passivation layer group comprises a first passivation layer, a first antireflection layer, and a second antireflection layer stacked in a direction away from the semiconductor substrate, and silicon content of the second antireflection layer is less than that of the first antireflection layer;
the body portion extends through the second antireflection layer; and
the first antireflection layer comprises a first portion and a second portion, and wherein an orthographic projection of the first portion on the semiconductor substrate does not overlap with an orthographic projection of the first electrode on the semiconductor substrate; the orthographic projection of the first electrode on the semiconductor substrate covers an orthographic projection of the second portion on the semiconductor substrate; and the second portion is provided between adjacent connecting portions.
10 . The solar cell according to claim 9 , wherein an area of orthographic projections of the plurality of connecting portions on the semiconductor substrate is a first area, and an area of the orthographic projection of the first electrode on the semiconductor substrate is a second area; and
a ratio of the first area to the second area ranges from 30% to 70%.
11 . The solar cell according to claim 1 , wherein the first electrode comprises first silver-containing particles and second silver-containing particles;
wherein particle diameters of the first silver-containing particles are greater than or equal to 1 nm and less than or equal to 100 nm, and particle diameters of the second silver-containing particles are greater than 100 nm and less than or equal to 300 nm; and
part of the first silver-containing particles and part of the second silver-containing particles are both in contact with the emitter.
12 . The solar cell according to claim 11 , wherein on a contact interface between the first electrode and the emitter, a quantity of particles of the first silver-containing particles is greater than a quantity of particles of the second silver-containing particles.
13 . The solar cell according to claim 12 , wherein on the contact interface between the first electrode and the emitter, the quantity of particles of the first silver-containing particles is a first value, a sum of the quantity of particles of the first silver-containing particles and the quantity of particles of the second silver-containing particles is a second value; and a ratio of the first value to the second value is no less than 80%.
14 . The solar cell according to claim 1 , wherein the emitter is made of crystalline silicon; and
a distance between a peak position of the emitter and a surface of the emitter away from the semiconductor substrate ranges from 0.1 μm to 0.6 μm; and/or
a junction depth of the emitter ranges from 0.1 μm to 1 μm.
15 . The solar cell according to claim 1 , further comprising:
a tunnel layer arranged on a side of the semiconductor substrate away from the emitter;
a doped semiconductor layer arranged on a side of the tunnel layer away from the semiconductor substrate; and
a second electrode arranged on a side of the doped semiconductor layer away from the tunnel layer, and electrically connected to the doped semiconductor layer;
wherein a thickness of the doped semiconductor layer ranges from 5 nm to 80 nm.
16 . The solar cell according to claim 1 , wherein the first electrode is made of a conductive paste, the conductive paste comprising:
a conductive powder;
a first glass frit comprising at least one of lead-containing glass and bismuth-containing glass; and
a second glass frit having a glass transition temperature greater than 600° C.;
wherein in the conductive paste, a weight percentage of the first glass frit ranges from 0.5% to 5%, and a weight percentage of the second glass frit ranges from 0.5% to 10%.
17 . The conductive paste according to claim 16 , wherein the second glass frit comprises one or more selected from a group consisting of a gold-containing alloy, a silicon-containing alloy, a manganese-containing alloy, a magnesium-containing alloy, a platinum-containing alloy, a tellurium-containing alloy, a palladium-containing alloy, a lithium-containing alloy, a nickel-containing alloy, a chromium-containing alloy, a barium-containing alloy, a zinc-containing alloy, and a cesium-containing alloy.
18 . The conductive paste according to claim 16 , wherein a total weight percentage of the first glass frit and the second glass frit ranges from 1% to 15%.
19 . The conductive paste according to claim 16 , wherein the conductive powder comprises silver powder;
wherein the conductive powder further comprises aluminum powder, and a weight percentage of the aluminum powder is no more than 1%.
20 . The solar cell according to claim 1 , wherein the plurality of connecting portions are arranged at uneven intervals on the side of the body portion.