On August 3, a research group led by Professor Choi Hyo-sung of the Department of Chemistry developed a defect control technology that improved the efficiency and stability of Perovskite 토토사이트 클럽비 cells, a technology referred to as new-generation 토토사이트 클럽비 cells. Perovskite, mostly used for 토토사이트 클럽비 cells, is a compound of organic cathode, lead, and halogen elements that absorb light with a semiconductor material that is based on the Perovskite structure. It can bind to various metal cathodes and is regarded as a new-generation 토토사이트 클럽비 cell as it is versatile thanks to its production cost and efficiency.

Professor Choi's work is significant in that it provided a material guideline for the commercialization of perovskite solar cells. The team's paper was recognized for its accomplishment as it was published in "Joule," an internationally renowned journal in material science. We talked to Professor Choi to get a more in-depth view of his work.

Even though many countries are tightening their regulations by proclaiming carbon neutrality, the energy demand has continued to increase. 토토사이트 클럽비 cells have been mentioned as an alternative that will satisfy such demand. However, due to the high cost and inefficiency, the existing silicon 토토사이트 클럽비 cells failed to become widespread.

Professor Choi's research on perovskite overcame the limitations of existing solutions and opened the possibilities of procuring source technology in developing new-generation 토토사이트 클럽비 cell material and devices. In his work, he focused on two aspects: perovskite defect control and passivation strategy through noncovalent bond interaction.

Perovskite defect refers to a condition where a change in the location of ions in a given material or atom reduces its functions. Among the different types of perovskite defects, Professor Choi focused on controlling iodine defects which could easily occur due to low formation energy.

"Perovskite defect is like your skin getting cut and infected," said Professor Choi. "Just like how the function in the surrounding area decreases once you have a wound, perovskite defects damage the structure, chemical homogeneity, and stability of solar cells, so you must control them to maintain the efficiency and stability of solar cells."

To effectively control perovskite defects, the researcher must first understand how strong pseudohalides (compounds that have similar charges as halide ions that are used for defect control) bond to the defects. Professor Choi said, "Upon investigating bond energy, we confirmed that noncovalent interaction between two materials plays a key role in deciding the bond energy."

Noncovalent bonds play an important role in our day-to-day life. For example, hydrogen bonds, non-covalent bonds between water molecules, let water have a boiling point and a melting point, and thanks to non-covalent interactions, biomolecules like DNA and proteins that can stably maintain their liquid form at room temperature can maintain a stable 3-dimensional structure.

The usage of noncovalent interaction in the study is significant in that it sheds light on the noncovalent interaction that has been undervalued. To control perovskite defects, an investigation of the bond energy of the defects must be preceded. Here, noncovalent bond plays a key role in deciding the bond energy.

Analyzing noncovalent interactions allows us to discern the most optimal pseudohalide materials which in turn can minimize defects when it is used in the synthesis of perovskites.

Professor Choi used a new passivation strategy (a technology that improves both performance and stability by treating defects chemically and physically) that approached pseudohalides from a supramolecular perspective, which improved the efficiency of 토토사이트 클럽비 cell modules and long-term stability in an environment with high humidity. The findings remain reliable in an actual environment, opening a possibility of commercialization as a new-generation 토토사이트 클럽비 cell.

"LOVE," the name of Professor Choi's laboratory, stands for the Lab for Optoelectronic and Versatile Energy Devices. Living up to the name of his lab, Professor Choi's love for his students is boundless. He who's been a professor for 10 years said, "My happiest moment is when I am working with over 20 students in my labs who brighten my day and give me good vibes."

He gave credit to his students for this 토토사이트 클럽비 as well.

"It took more than 2 years to complete the research, and it wasn't an easy one. Yet every time I felt that way, my students gave me the strength to continue. One time, a lab instrument was broken which could have delayed the research, but one student worked day and night to fix it. Whenever I witness students putting everything they have into their research, it really inspires me to work harder."

In addition, Professor Choi gave words of advice to Hanyang students who will conduct various 토토사이트 클럽비.

"I want to say two things. First, have at least 2 to 3 friends with whom you can freely share anything. If you are pursuing a doctoral degree, at some point in this long journey, you are going to end up feeling like you're stuck, but friends really do help you go through that time. Second, work out. Go to gyms. You need a healthy body to support a healthy mind. I am rooting for all Hanyang students who continuously strive for their dreams. Cheers!"