# US 11,309,441 B2 · Solar cell

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- Number: US 11,309,441 B2
- Document ID: US11309441B2
- Status: Granted
- Kind: B2
- Application number: 14/243,724
- Filed: 2014-04-02
- Published: 2014-10-09
- Granted: 2022-04-19
- Earliest claimed: 2013-04-03
- Assignees: LG Electronics Inc.
- Applicants: LG Electronics Inc.
- Inventors: Jaewon Chang; Kyungjin Shim; Hyunjung Park; Junghoon Choi
- Web page: https://patentgrep.com/patent/US11309441B2

## CPC

- H10F 77/311: {for photovoltaic cells}
- H10F 10/14: Photovoltaic cells having only PN homojunction potential barriers
- H10F 10/166: the Group IV-IV heterojunctions being heterojunctions of crystalline and amorphous materials, e.g. silicon heterojunction [SHJ] photovoltaic cells
- H10F 71/00: Manufacture or treatment of devices covered by this subclass (patterning processes to connect thin photovoltaic cells in integrated devices, or assemblies of multiple devices, having photovoltaic cells H10F19/33; manufacture or treatment of encapsulations or containers for integrated devices, or assemblies of multiple devices, having photovoltaic cells H10F19/80; manufacture or treatment of integrated devices, or assemblies of multiple devices, comprising at least one element in which radiation controls the flow of current H10F39/00)
- H10F 71/121: {The active layers comprising only Group IV materials}
- H10F 71/1221: {comprising polycrystalline silicon}
- H10F 71/128: {Annealing}
- H10F 71/129: {Passivating}
- H10F 77/1642: {including only Group IV materials}
- H10F 77/1692: {the films including only Group IV materials}
- H10F 77/211: {for photovoltaic cells}
- H10F 77/315: {the coatings being antireflective or having enhancing optical properties}
- C23C 16/24: Deposition of silicon only
- H10W 70/098: {Applying pastes or inks, e.g. screen printing (H10W70/095 takes precedence)}
- Y02E 10/50: Photovoltaic [PV] energy
- Y02E 10/547: Monocrystalline silicon PV cells
- H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION
- C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04)
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

Discussed is a solar cell including a semiconductor substrate, a first tunneling layer entirely formed over a surface of the semiconductor substrate, a first conductive type area disposed on the surface of the semiconductor substrate, and an electrode including a first electrode connected to the first conductive type area.

## Claims

### Claim 1

A solar cell comprising:
a monocrystalline silicon substrate;
a tunneling layer formed of one of nitride, oxide and oxide nitride, and formed directly on a rear surface of the monocrystalline silicon substrate;
a first back surface field layer directly formed over the tunneling layer and formed of a polycrystalline silicon;
a second back surface field layer positioned inside of the rear surface of the monocrystalline silicon substrate, thereby the tunneling layer is between the first back surface field layer and the second back surface field layer, wherein the second back surface field layer is formed of a monocrystalline silicon;
an emitter layer positioned inside of a front surface of the monocrystalline silicon substrate;
a first insulating film formed on the first back surface field layer;
a second insulating film formed on the emitter layer;
a first electrode directly connected to the first back surface field layer through a plurality of first openings of the first insulating film; and
a second electrode directly connected to the emitter layer through a plurality of second openings of the second insulating film,
wherein the first electrode physically contacts the first back surface field layer and does not directly physically contact the second back surface field layer, and
wherein the tunneling layer has a thickness of 0.5 nm to 5 nm, and the first back surface field layer has a thickness of 50 nm to 500 nm.

### Claim 2 (depends on 1)

The solar cell according to claim 1, wherein the tunneling layer comprises at least one of silicon oxide, silicon nitride, and silicon oxide nitride.

### Claim 3 (depends on 1)

The solar cell according to claim 1, wherein a ratio of a doping concentration of the first back surface field layer to a doping concentration of the second back surface field layer is 5 to 10.

### Claim 4 (depends on 1)

The solar cell according to claim 1, wherein a ratio of a thickness of the first back surface field layer to a thickness of the second back surface field layer is 10 to 50.

### Claim 5 (depends on 1)

The solar cell according to claim 1, wherein the tunneling layer is thinner than the first back surface field layer and the second back surface field layer.

### Claim 6 (depends on 1)

The solar cell according to claim 1, wherein the first back surface field layer and the second back surface field layer have a same dopant.

### Claim 7 (depends on 1)

The solar cell according to claim 1, wherein a first region of the emitter layer connected to the second electrode has a resistance lower than a resistance of a second region of the emitter layer where the second electrode is not in direct contact.

### Claim 8 (depends on 1)

The solar cell according to claim 1, wherein light is incident to the rear surface of the monocrystalline silicon substrate through a portion where the first electrode is not formed.

### Claim 9 (depends on 1)

The solar cell according to claim 1, wherein the first insulating film or the second insulating film includes at least one of aluminum oxide, zirconium oxide, and hafnium oxide having a negative charge.

### Claim 10 (depends on 1)

The solar cell according to claim 1, wherein the first insulating film or the second insulating film includes at least one of silicon oxide and silicon nitride having a positive charge.

### Claim 11 (depends on 1)

The solar cell according to claim 1, wherein the first insulating film or the second insulating film is a single film or a multilayer film including two or more films.

### Claim 12 (depends on 1)

The solar cell according to claim 1, further comprising an anti-reflection film on the first insulating film or the second insulating film.

### Claim 13 (depends on 1)

The solar cell according to claim 1, wherein the tunneling layer has the thickness of 0.5 nm to 2 nm.

### Claim 14 (depends on 1)

The solar cell according to claim 1, wherein the first electrode comprises:
a plurality of finger electrodes having a first pitch and being disposed in parallel to each other; and
a plurality of bus bar electrodes which are formed in a direction crossing the plurality of finger electrodes to be parallel to each other and having a second pitch larger than the first pitch.

### Claim 15 (depends on 1)

The solar cell according to claim 1, wherein the second back surface field layer includes a dopant included in the first back surface field layer.

### Claim 16 (depends on 1)

The solar cell according to claim 1, wherein a doping concentration of an area of the first back surface field layer adjacent to the first electrode is higher than a doping concentration of an area of the first back surface field layer adjacent to the tunneling layer.

### Claim 17 (depends on 16)

The solar cell according to claim 16, wherein a doping concentration of the first back surface field layer is higher than a doping concentration of the second back surface field layer.

### Claim 18 (depends on 1)

The solar cell according to claim 1, wherein the emitter layer a thickness of 5 nm to 100 nm.

### Claim 19 (depends on 1)

The solar cell according to claim 1, wherein the first electrode further does not directly physically contact the tunneling layer, and
wherein the first electrode has a textured surface that corresponds to the texturing of the monocrystalline silicon substrate.

### Claim 20 (depends on 1)

The solar cell according to claim 1, wherein the thickness of the first back surface field layer is 10 to 1,000 times the thickness of the tunneling layer.