Canon : develops high performance materials for perovskite solar cells to improve substantial durability and mass production stability

TOKYO, June 18, 2024-Canon Inc. announced today that it has developed a high-performance material which is expected to improve the durability and mass-production stability of perovskite solar cells. The company will further develop the technology and aims to initiate mass production in 2025.

Solar cells are becoming widely used as an effective means of realizing a decarbonized society. Today, silicon solar cells are dominantly used in many solar panels for homes and businesses. However, since glass is used as a substrate, these panels can only be installed in places that are sturdy enough to withstand their weight, which has so far been an issue. By comparison, perovskite solar cells are lightweight, bendable, and can generate electricity even from indoor lighting, thereby offering a greater degree of freedom in installation than silicon solar cells. Additionally, they are expected to reduce capital investment costs because they do not require extensive equipment to manufacture. For these reasons, they are attracting attention as the next generation of solar cells.

At the same time, however, there are several issues standing in the way of practical application. For one, it is known that the crystal structure of the perovskite layer (photoelectric conversion layer) is susceptible to the effects of water, heat, oxygen, etc. in the atmosphere, which results in low durability. Furthermore, it is difficult to achieve stable mass production when manufacturing perovskite solar cells with a large surface area. It has been recognized that a structure covering the perovskite layer is needed to solve these problems. Therefore, Canon developed a special functional material to coat the perovskite layer by applying the material technology it cultivated through the development of photosensitive members, a key component of multifunction office devices and laser printers.

The key characteristic of this material is its ability to cover the perovskite layer thickly while maintaining a high rate of photoelectric conversion efficiency, which has been difficult with conventional materials. The material can be coated at a thickness of 100-200 nm, whereas the conventional coating layer is several tens of nm*. Through joint research with Professor Dr. Tsutomu Miyasaka, inventor of the perovskite solar cell and faculty member at Toin University of Yokohama, a performance evaluation was conducted, the results of which verified its potential to improve the durability of perovskite solar cells and showed promise in advancing the stability of mass production. It is anticipated that solving these hurdles will help contribute to more widespread use. "By adding a layer of this newly developed high-performance material to the layer structure of these cells, we can expect to solve the issue of mass production," said Professor Miyasaka.

Canon will begin shipping samples of this material in June 2024 in an aim to collaborate with companies engaged in the mass production of perovskite solar cells. Going forward, the company will work on further technological development and intends to start mass production in 2025.

Canon will create new value through the power of technology and innovation, while also contributing to solutions for the problems our society faces.

* 1nm (nanometer) = 1/1,000,000,000 m

Publication of papers on the material

A paper, coauthored by Toin University of Yokohama and Canon, summarizing the research results of this material was published in the Journal of Materials Chemistry A, a peer-reviewed international journal issued by the Royal Society of Chemistry in the U.K. under the following title:

"Phthalocyanine-Based Polycrystalline Interlayer Simultaneously Realizing Charge Collection and Ion Defect Passivation for Perovskite Solar Cells"

Link to publication: https://pubs.rsc.org/en/content/articlelanding/2024/ta/d4ta02491e

Overview of the newly developed material

When the perovskite layer is covered with the material developed by Canon, the coating suppresses the loss of substance in the crystal structure, which helps to improve the durability of perovskite solar cells. Since the newly developed material has the property of a semiconductor, a high rate of photoelectric conversion efficiency is maintained even if the perovskite layer is thickly coated, which is expected to improve mass-production stability.

Properties of Photoelectric Conversion Layers in Perovskite Solar Cells

The crystal structure in the perovskite layer deteriorates due to the impact of water, heat, oxygen, etc. in the atmosphere, which lowers the durability of perovskite solar cells.