Can Self-Healing Solar Cells Heal at Night?

Perovskite solar cells degrade when exposed to sunlight, causing performance degradation over time. A new research study will examine how such solar cells can heal and repair themselves at night.

Professor of Physics Ellen Moons states that solar cells and LEDs are made of semiconductor materials. These materials are responsible for developing the basis of all computers, electronic devices, displays and mobile phones. Halide perovskite is a new type of semiconductor and is known to be of great interest to achieve high performance as a solar cell material, which is easy and efficient to manufacture.

The disadvantage of these perovskite solar cells is that their performance degrades over time. It would be extremely beneficial, especially from an environmental point of view, if solar cells could help repair themselves, which may sound like science fiction, but it has been pointed out in several materials.

Research Cooperation with Israeli Universities

The study was carried out as a cooperation project between Karlstad University and Ben-Gurion University of the Negev and the Weizmann Institute of Science in Israel. Metal halide perovskite is considered a new category of semiconductor that has been shown to have self-healing potential.

They can be used for high efficiency LEDs and solar cells. One of the Israeli research groups has shown that metal halide perovskite solar cells that degrade in sunlight can regain their effectiveness when the night turns out to be dark.

The other research group from Israel has uncovered single crystals of lead-based metal halide perovskites up to powerful lasers, causing them to lack their ability to glow. In addition, the scientists discovered that the material helped restore its photoluminescence after several recovery periods in the dark.

Also, although these two observations, one in the thin, polycrystalline layer of the solar cell and the other in single crystals, appear to be related, it is still difficult to know what the possible relationship between these two phenomena is or how it works.

According to Ellen Moons, in order to understand the self-healing mechanics of such materials, it is important to be involved in this project, analyzing a large number of samples with and without an interface layer.

The role of interface layers in preventing ions and degradation products from leaving the perovskite layer will be analyzed. Moreover, such degradation products can be recycled to reverse the process and repair metal halide perovskites.

Collaborating research groups will use non-destructive analytical techniques to determine which bonds in the material experience changes in degradation and repair processes. They will also analyze what effects these shifts have on the electronic properties of the material.

Sustainable Development and Renewable Energy Research

Ellen Moons states that this project will lead to new and sustainable semiconductor materials. The materials produced will be energy efficient to be produced and will be able to regenerate their properties once the degradation is done.

Currently, learning about self-healing semiconductor electronics is predicted to have significant value in the development of future renewable energy sources and also includes the development of sustainable electronics.

The project was financially supported through SSF, the Swedish Strategic Research Foundation. About eight research projects will share approximately SEK 50 million provided by the “High School Meitner Grants for Israeli-Swedish Research Cooperation”, a bilateral collaboration between SSF and MOST, the Israeli Ministry of Science, Technology and Space.

Source: https://www.kau.se/en