KU Presents a New Design Direction for Next-Generation Solar Cells

to Improve Both Safety and Efficiency

Korea University (President Kim Dong-one) presents a new design direction for perovskite solar cells, which have drawn attention as a next-generation energy source.
*Device: Individual parts that are components of an apparatus or electronic circuit.

The research results were published in Energy & Environmental Science (impact factor: 32.4), a globally renowned journal for the energy field, on July 23.

Perovskites are thinner and lighter and have higher stability and efficiency compared to silicon materials used for existing solar cells. They are also easy to manufacture, so they have drawn significant attention as a solar cell material. However, the reasons why perovskites are so efficient have not been sufficiently studied to date.

Professor Noh Jun-hong’s group in the School of Civil, Environmental and Architectural Engineering proposed a new design direction for 2D perovskite devices and discovered the principles associated with improving their performance and stability. The research group fabricated a 3D/2D perovskite bilayer structure (known as a heterojunction) to analyze the characteristics of 2D perovskites.
*The inter structure of the same material may vary according to the dimensions (1D, 2D, or 3D). For example, a carbon material is graphite when it is 2D and is diamond when it is 3D.

The results revealed that the magnitude and distribution of the electric field were altered by controlling the work function of the 2D perovskite. Based on this, the research group found that 2D perovskites are capable of treating defects (imperfections in the material structure) at the heterojunctions and controlling the flow of charge carriers (particles that can freely move with an electric charge).
*Work function: Energy required to release a single electron (electromagnetic particle) in a vacuum (Unit: electronvolt (eV)).
*Electric field: Electrical characteristics expressed in the space around an electrically charged object.

Professor Noh, the corresponding author of the article, said, “Our results showed that convergent studies on materials and devices are needed to achieve a perovskite solar cell efficiency of 27% or higher.”

This study was supported by the Korea Research Institute for Defense Technology Planning and Advancement (KRIT), the Mid-Carrier Research Fund of the National Research Foundation of Korea supported by the Ministry of Science and ICT, the Carbon Neutral Technology Program, and the Energy Human Resource Fostering Program of the Korea Energy Technology Evaluation and Planning (KETEP) supported by the Ministry of Trade, Industry and Energy (Energy Innovation Research Center).

[Figure 1] 

▲ Schematic diagram illustrating the magnitude and distribution of the internal electric potential depending on the 2D perovskite material.

[Figure 2] 

▲ Measurements of solar cell stability according to the application of the 2D perovskite materials.