Solar cell and method for manufacturing the same

Patent metadata

Field	Value
Publication number	US-2019319140-A1
Application number	US-201916456915-A
Country	US
Kind code	A1
Filing date	Jun 28, 2019
Priority date	Nov 28, 2014
Publication date	Oct 17, 2019
Grant date	—

Abstract

A solar cell can include a silicon substrate; a tunnel layer disposed on a first surface of the silicon substrate, the tunnel layer including a dielectric material; a polycrystalline silicon layer disposed on the tunnel layer; a dielectric layer disposed on the polycrystalline silicon layer; and an electrode penetrating through the dielectric layer and directly contacting with the polycrystalline silicon layer, wherein the polycrystalline silicon layer includes a metal crystal region positioned at a region where the polycrystalline silicon layer contacts the electrode, and wherein the metal crystal region includes a plurality of metal crystals, the plurality of metal crystals including a metal material same as a metal material included in the electrode.

First claim

What is claimed is:

1 . A solar cell, comprising:
a silicon substrate; a tunnel layer disposed on a first surface of the silicon substrate, the tunnel layer including a dielectric material; a polycrystalline silicon layer disposed on the tunnel layer; a dielectric layer disposed on the polycrystalline silicon layer; and an electrode penetrating through the dielectric layer and directly contacting with the polycrystalline silicon layer, wherein the polycrystalline silicon layer includes a metal crystal region positioned at a region where the polycrystalline silicon layer contacts the electrode, and wherein the metal crystal region includes a plurality of metal crystals, the plurality of metal crystals including a metal material same as a metal material included in the electrode.

2 . The solar cell according to claim 1 , wherein the plurality of metal crystals include a contact metal crystal directly contacting with the electrode.

3 . The solar cell according to claim 1 , wherein the plurality of metal crystals include an inner metal crystal positioned at an inside of the polycrystalline silicon layer, the inner metal crystal being spaced apart from the electrode.

4 . The solar cell according to claim 1 , wherein the plurality of metal crystals are positioned in a portion of the polycrystalline silicon layer that is closer to the electrode than the tunnel layer.

5 . The solar cell according to claim 1 , wherein the metal crystal region is positioned at a depth within ⅔ of a thickness of the polycrystalline silicon layer from a surface of the polycrystalline silicon layer.

6 . The solar cell according to claim 1 , wherein the plurality of metal crystals are positioned at a region where the polycrystalline silicon layer contacts the electrode.

7 . The solar cell according to claim 1 , wherein the tunnel layer is free of metal crystals.

8 . The solar cell according to claim 1 , wherein at least a part of the electrode protrudes into the polycrystalline silicon layer.

9 . The solar cell according to claim 1 , further comprising:
a doping region formed at a second surface of the silicon substrate by a diffusion of a dopant; and another electrode connected to the doping region.

10 . The solar cell according to claim 1 , wherein the electrode includes a plurality of finger electrodes extending in a first direction and a bus electrode extending in a second direction crossing the first direction,
wherein a first region of the polycrystalline silicon layer directly contacts with the plurality of finger electrodes and includes a portion of the plurality of metal crystals, and wherein a second region of the polycrystalline silicon layer directly contacts with the bus electrode and is spaced apart from the plurality of metal crystals.

11 . The solar cell according to claim 1 , wherein the electrode includes a metal material and a glass frit.

12 . The solar cell according to claim 1 , wherein the electrode includes a plurality of finger electrodes extending in a first direction and a bus electrode extending in a second direction crossing the first direction, and
wherein a composition of the plurality of finger electrodes is different from a composition of the bus electrode.

13 . The solar cell according to claim 12 , wherein an amount of glass frit per unit volume in the plurality of finger electrodes is different from an amount of glass frit per unit volume in the bus electrode.

14 . The solar cell according to claim 13 , wherein the amount of glass frit per unit volume in the plurality of finger electrodes is less than the amount of glass frit per unit volume in the bus electrode.

15 . The solar cell according to claim 13 , wherein the plurality of finger electrodes include glass frit, and
wherein the bus electrode is free of glass frit.

16 . The solar cell according to claim 13 , wherein an amount of the metal material per unit volume in the plurality of finger electrodes is greater than an amount of the metal material per unit volume in the bus electrode.

17 . The solar cell according to claim 12 , wherein at least a part of the electrode protrudes into the polycrystalline silicon layer, and
wherein a degree that the plurality of finger electrodes protrude into the polycrystalline silicon layer is greater than a degree that the bus electrode protrudes into the polycrystalline silicon layer.

18 . The solar cell according to claim 12 , wherein the plurality of finger electrodes penetrate through the dielectric layer and protrude into the polycrystalline silicon layer, and
wherein the bus electrode is spaced apart from the polycrystalline silicon layer on the dielectric layer.

19 . A method for manufacturing a solar cell, the method comprising:
forming a tunnel layer on a surface of the silicon substrate, the tunnel layer including a dielectric material; forming a polycrystalline silicon layer on the tunnel layer; forming a dielectric layer on the polycrystalline silicon layer; printing an electrode pattern on the dielectric layer; and forming an electrode penetrating through the dielectric layer and directly contacting with the polycrystalline silicon layer, wherein, in the forming the electrode, a metal crystal region is formed in the polycrystalline silicon layer at a region where the polycrystalline silicon layer directly contacts the electrode, and wherein the metal crystal region includes a plurality of metal crystals, the plurality of metal crystals including a metal material same as a metal material included in the electrode.

20 . The method according to claim 19 , wherein the electrode includes a plurality of finger electrodes extending in a first direction and a bus electrode extending in a second direction crossing the first direction, and
wherein the plurality of finger electrodes and the bus electrode have a same composition, and pastes for the plurality of finger electrodes and the bus electrode are simultaneously printed in the printing the electrode pattern.

21 . The method according to claim 19 , wherein the electrode includes a plurality of finger electrodes extending in a first direction and a bus electrode extending in a second direction crossing the first direction, and
wherein a first paste for the plurality of finger electrodes has a different composition than a second paste for the bus electrode, and the first paste and the second paste are separately printed in the printing the electrode pattern.

22 . The method according to claim 21 , wherein an amount of glass frit per unit volume in the first paste is different from an amount of glass frit per unit volume in the second paste.

23 . The method according to claim 19 , wherein the electrode includes a plurality of finger electrodes extending in a first direction and a bus electrode extending in a second direction crossing the first direction, and
wherein, in the forming the electrode, the plurality of metal crystals are formed in a region of the polycrystalline silicon layer where the polycrystalline silicon layer directly contacts with the plurality of finger electrodes, and the plurality of metal crystals are not formed in a region of the polycrystalline silicon layer where the polycrystalline silicon layer directly contacts with the bus electrode.

24 . The method according to claim 19 , wherein the electrode includes a plurality of finger electrodes extending in a first direction and a bus ele

Assignees

• Lg Electronics Inc

Inventors

• Ha Jungmin
• Kim Sungjin
• Cheong Juhwa
• Ahn Junyong
• Choi Hyungwook
• Chang Wonjae
• Kim Jaesung

Classifications

• Y02E10/50

  Photovoltaic [PV] energy · CPC title

• H01L31/077

  Electricity · mapped topic

• H01L31/1868

  Electricity · mapped topic

• H01L31/02167

  Electricity · mapped topic

• H01L31/022425

  Electricity · mapped topic