Yousheng Wang, Tahmineh Mahmoudi and Prof. Yoon-Bong Han (Dept. of Chemical Engineering) announced the results of developing a functional nanocomposite material and applying it to perovskite solar cells, which are drawing attention as next-generation solar cells. The results are recently published online in Advanced Energy Materials (IF=24.884), a world-renowned academic journal in the field of high-tech energy materials.

 

The perovskite solar cell is in the spotlight as a next generation solar cell that can replace the silicon solar cell, but due to optical/thermal instability, ion migration and decomposition of the perovskite material by water when exposed to air for a long time. It has the problem of significantly shortening the life and efficiency of the solar cell. Therefore, for practical use of the perovskite solar cell, it is necessary to develop a material capable of securing long-term stability while maintaining high efficiency.

 

The perovskite molecule is composed of a combination of organic and inorganic cations and halogen anions, and organic cations have an important effect on crystal structure and stability.

 

The team have developed various nanocomposite materials and applied the research results to perovskite solar cells. The study results were published in Advanced Energy Materials (IF=24.884), ACS Energy Letters (IF=16.331) and Nano Energy (IF=15.548).

 

This time, the research team made a perovskite molecule by optimally mixing two types of organic cations (MA and FA), and then mixing this with copper-doped nickel oxide (Cu:NiO) to form a functional composite material (FAMA-Perovskite)-Cu:NiO).

 

As a result of applying the prepared functional composite material to the active layer of the perovskite solar cell, a high-performance solar cell with a photocurrent density of 24.5 mA/cm2, a fill factor of 80.5%, and a light conversion efficiency of 20.7% or more, could be manufactured.

 

In addition, the thermal optical stability and the stability to air have been greatly improved, and the result is that the solar cell efficiency is stably maintained at 97% or more even after 240 days in atmospheric conditions.

 

"We made chemical, thermal and optically unstable perovskite molecules into functional nanocomposite materials with excellent stability, and applied them to the active layer of perovskite solar cells," said Prof. Han. "It is significant that the cause of the problem, which is a stumbling block, was theoretically identified and a solution was proposed through experiments."