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Perovskite is a kind of semiconductor material, which has attracted the interest of scientists all over the world. Their unique crystal structure makes them have excellent optical and electronic properties, and they are simple and cheap to manufacture.

Although most progress has been made in the research of solar cells using perovskite, they are also very suitable for manufacturing led.

In recent years, the efficiency of perovskite LED has been significantly improved, and will soon reach the efficiency of competitive technology. However, they are not particularly stable, which means that they cannot be put into practical application at present.

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Recently, researchers from Linxueping University in Sweden cooperated with colleagues from Britain, China and Czech Republic to develop a perovskite light-emitting diode with high efficiency and long-term stability. The research results were published in the journal Nature Communications.

Professor Gao Feng, director of the department of biomolecular and organic electronics at Lin Xueping University, said: "Perovskite-based light-emitting diodes are not stable enough in practical application, but we have made them take a step toward this goal."

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Liu Xiaoke, a researcher in the Department of Biomolecules and Organic Electronics at Lin Xueping University and the first author of this paper, said with Gao Feng, "There is still a lot of work to be done. At present, most perovskite LEDs are either inefficient or have poor device stability. "

Many scientific research groups have tried to get rid of this dilemma, but they have not achieved remarkable success. Recently, researchers from the University of Linxueping in Sweden, together with their colleagues in Britain, China and the Czech Republic, found a way forward. They used a perovskite composed of lead, iodine and formamidine, and then embedded this perovskite into the organic molecular matrix to form a composite membrane.

Wang, a doctoral student in the department of biomolecular and organic electronics, said: "This molecule contains two amino groups at the end, which helps other substances to form high-quality crystal structures. This is the characteristic of perovskite, which makes the crystal stable. "

This new composite film enables the research team to develop an LED with an efficiency of 65,438+07.3% and a half-life of about 65,438+000 hours.

This perovskite containing lead and halogen (iodine in this case) has the best luminescent characteristics.

Gao Feng said, "We really want to remove lead. At present, we have found a good way, but we are working hard. "

The next step is to test different combinations of perovskite and organic molecules and learn more about how the nucleation and crystallization processes occur. Different perovskite endows light with different wavelengths, which is a necessary condition to realize the long-term goal of white LED.

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Reference materials?

1 Wang Heyong, Felix Utama Kosasih, Yu Hongling, Zheng Guanhao, Zhang, Galia Pozina, Bao Chunxiong, Liu Xianjie, Libor Kobera, Sabina Abbrent, Jiri Brus, Yizheng Jin, Mats Fahlman, Richard H. Friend, Caterina Ducati. Perovskite-molecular composite films for efficient and stable light emitting diodes. Natural newsletter, 2020; 1 1( 1)DOI: 10. 1038/s 4 1467-020- 14747-6

2 https://Liu . se/en/news-item/ett-steg-NAR mare-en-stabil-Lys diod-I-perovskit