Photoelectric conversion element, photoelectric conversion module, and solar photovoltaic power generation system

Patent metadata

Field	Value
Publication number	US-2016268459-A1
Application number	US-201415031838-A
Country	US
Kind code	A1
Filing date	Oct 24, 2014
Priority date	Oct 25, 2013
Publication date	Sep 15, 2016
Grant date	—

Abstract

There is provided a photoelectric conversion element which can prevent the contact resistance between a non-crystalline semiconductor layer containing impurities and an electrode formed on the non-crystalline semiconductor layer from increasing, and can improve the element characteristics. A photoelectric conversion element ( 10 ) includes a semiconductor substrate ( 12 ), a first semiconductor layer ( 20 n ), a second semiconductor layer ( 20 p ), a first electrode ( 22 n ), and a second electrode ( 22 p ). The first semiconductor layer has a first conductive type. The second semiconductor layer has a second conductive type. The first electrode is formed on the first semiconductor layer. The second electrode is formed on the second semiconductor layer. The first electrode includes a first transparent conductive layer ( 26 n ) formed on the first semiconductor layer, and a first metal layer ( 28 n ) formed on the first transparent conductive layer. The first metal layer includes a plurality of metal crystal grains in which the average crystal grain size in the in-surface direction of the first metal layer is greater than the thickness of the first metal layer.

First claim

1 . A photoelectric conversion element comprising:
a semiconductor substrate; a first semiconductor layer having a first conductive type; a second semiconductor layer having a second conductive type opposite to the first conductive type; a first electrode which is formed on the first semiconductor layer; and a second electrode which is formed on the second semiconductor layer, wherein the first electrode includes a first transparent conductive layer formed on the first semiconductor layer and a first metal layer formed on the first transparent conductive layer, wherein the first metal layer includes a plurality of metal crystal grains, and wherein the average crystal grain size of the metal crystal grain in the in-surface direction of the first metal layer is greater than the thickness of the first metal layer.

2 . The photoelectric conversion element according to claim 1 ,
wherein the first electrode is made of a metal film which has silver as a main component.

3 . The photoelectric conversion element according to claim 1 ,
wherein the first semiconductor layer and the second semiconductor layer are formed on a rear surface opposite to a light-receiving surface on the semiconductor substrate.

4 . The photoelectric conversion element according to claim 1 ,
wherein, in the metal crystal grains, a crystal axis which is parallel to the thickness direction of the semiconductor substrate is preferentially oriented in the <111> direction.

5 . The photoelectric conversion element according to claim 1 ,
wherein the first conductive type is an n-type, and wherein the average crystal grain size is less than 3.33 times the thickness of the first metal layer.

6 . The photoelectric conversion element according to claim 1 ,
wherein the first conductive type is the n-type, and wherein the average crystal grain size is 2.85 times or less than the thickness of the first metal layer.

7 . The photoelectric conversion element according to claim 1 ,
wherein the first conductive type is the n-type, and wherein the average crystal grain size is 1.55 times or greater and 2.85 times or less than the thickness of the first metal layer.

8 . The photoelectric conversion element according to claim 1 ,
wherein the first conductive type is a p-type, and wherein the average crystal grain size is 3.3 times or less than the thickness of the first metal layer.

9 . The photoelectric conversion element according to claim 1 ,
wherein the first conductive type is a p-type, and wherein the average crystal grain size is 1.03 times or greater and 2.95 times or less than the thickness of the first metal layer.

10 . The photoelectric conversion element according to claim 1 ,
wherein the first conductive type is the p-type, and wherein the average crystal grain size is 1.53 times or greater and 2.15 times or less than the thickness of the first metal layer.

11 . The photoelectric conversion element according to claim
1 , wherein a second electrode includes a second transparent conductive layer formed on the second semiconductor layer, and a second metal layer formed on the second transparent conductive layer, wherein the second metal layer includes a plurality of metal crystal grains, wherein a contact area between the second electrode and the second semiconductor layer is 1 times or greater than the contact area between the first electrode and the first semiconductor layer, and wherein an average value of the average crystal grain size of the metal crystal grain in the first metal layer, and the average crystal grain size of the metal crystal grain in the second metal layer, is 1.03 times or greater and 2.15 times or less than the thickness of the first metal layer and the second metal layer.

12 . A photoelectric conversion module comprising:
at least one photoelectric conversion element according to claim 1 .

13 . A solar photovoltaic power generation system comprising:
at least one photoelectric conversion module according to claim 12 .

Assignees

• Sharp Kk

Inventors

• Kimoto Kenji
• Koide Naoki
• Matsumoto Yuta
• Nakamura Junichi

Classifications

• H02S10/00

  PV power plants; Combinations of PV energy systems with other systems for the generation of electric power · CPC title

• Y02E10/547

  Monocrystalline silicon PV cells · CPC title

• H10F77/311

  for photovoltaic cells · CPC title

• H10F77/219

  Arrangements for electrodes of back-contact photovoltaic cells · CPC title

• H10F77/211

  for photovoltaic cells · CPC title