• Yomiuri Editorial

Next-Generation Solar Cells: Accelerate Decarbonization Efforts with Japan-Originated Technology

Next-generation solar cells based on Japan-originated technology have attracted growing attention as a method for realizing decarbonization. As global competition for developing such technology has intensified, Japan should take advantage of its technological superiority to accelerate efforts to commercialize next-generation solar cells.

Such next-generation cells are called perovskite solar cells. Perovskite is a material with a certain crystal structure. It can be manufactured by dissolving a compound that has this structure in a solution and using it to coat a film or other material.

Currently, most solar cells are made of silicon, but silicon is easily broken and needs to be protected by tempered glass.

As perovskite solar cells can be processed into sheets, their characteristics include being lightweight and bendable.

These cells can be affixed to objects such as building walls, windows and the roofs of electric vehicles. They can generate electricity even with weak indoor light, and have also been envisaged for use in smartphones and information technology devices.

Tsutomu Miyasaka, a specially appointed professor at Toin University of Yokohama, has pioneered the development of this technology and published a paper on it in 2009. It is hoped that Japan will take the lead in putting the technology into practical use in order to lead the world in decarbonization.

Japan, with its many mountainous areas, does not have many suitable locations for conventional solar power generation, but the use of perovskite solar cells will greatly increase and expand potential installation locations.

Iodine, a key material in making perovskite, is widely used in products such as disinfectants, and Japan is the world’s second-largest producer of this material. As Japan is dependent on imports of natural resources, this technology is also highly important from the standpoint of energy security.

The technology for power generation using perovskite solar cells has been already established, so a future challenge is to improve the technology for mass production.

The government aims to put perovskite solar cells into practical use by 2025. So far, it has secured funding of about ¥50 billion, with which it has backed companies in conducting research and development on the mass production of perovskite solar cells.

In Japan, Sekisui Chemical Co. has begun tests toward mass production by installing perovskite solar cells on exterior walls of its facilities. Other companies, such as Panasonic Holdings Corp., Toshiba Corp. and chemical manufacturer Kaneka Corp., are also working to commercialize the cells.

Japan has led the world in basic research on perovskite solar cells. However, in terms of mass production to commercialize the cells, Japan is said to have fallen behind China and European countries, which are vigorously pursuing development in the field. It is an urgent task for Japan to improve its production system.

Japan once held a majority share of the global market for silicon solar cells, but later lost ground to Chinese companies in a price war that drove Japanese firms out of the market one after another. Currently, China holds more than 80% of the world’s production capacity for silicon solar cells.

Japan must not repeat the same mistake with the perovskite solar cells that it originated itself. In addition to the government’s intensive support, it should be necessary to strengthen cooperation among relevant companies.

(From The Yomiuri Shimbun, Feb. 3, 2024)