KAIST Prof. Park Jung-yeong's team publishes study in September 14 issue of 'Nano Letters' a leading nano science journal

The National Research Foundation of Korea (Chairman: Oh Se-jung) said, on October 6, that Korean scientists had developed a fundamental technology for hot electron solar cells that are created by absorbing solar light. The study was led by Prof. Park Jeong-young at the EEWS Graduate School in the Korea Advanced Institute of Science and Technology (KAIST, President: Suh Nam-pyo) and was assisted by master's program student Lee Young-keun and doctoral student Jung Chan-ho.

Prof. Park's team detected hot electrons generated on the surface of nanodiode by light by using a nanodiode that consisted of a metal thin film and a metal oxide semiconductor, and transformed them into a nanosome measuring dozens of nanometers through surface treatment of the metal thin film of the nanodiode. This nanosome displayed a surface plasmon. The research team measured the hot electrons detected on nanodiode, and thus examined the amplification of hot electrons due to a surface plasmon. This suggested that a surface plasmon maximizes the generation of hot electrons, and this principle can be applied to increasing the efficiency of solar cells.

Prof. Park said, "Accurately understanding and measuring hot electron is very important in surface science and energy engineering because it allows us to fundamentally understand the process of energy loss. The development of this fundamental technology related to hot electrons is expected to have applications in the development of high efficiency transformation devices."

The study was published online first on September 14 in Nano Letters, a prestigious journal in the nano science field.

#?Glossary

o Hot electron
Hot electrons are generated on the surface due to energy conversion process when energy is transferred to the surface from outside. In this process, external energy entails various phenomena, including chemical reactions, such as the absorption of light, the absorption of molecules and catalytic reactions, or the colliding of electrons or ions. Converted energy allows for the flow of hot electrons on the surface. The detection of such hot electrons is possible by using a nanodiode comprised of a thin film oxide. Understanding and measuring these hot electrons holds significance in that it allows the process of energy loss at the molecular level to be better understood.

o Surface Plasmon
This refers to quasi particles in which free electrons vibrate collectively on the surface of a metal. The phenomenon whereby light is contained on the surface of a metal, due to the interaction of light and free electrons within the metal, is called surface plasmon resonance. As a result of this surface plasmon resonance, the intensity of the metal?s electromagnetic field increases. The cross-section where light is absorbed by a metal changes due to a surface plasmon, and as a result, the penetration ratio of light changes at a certain wavelength at which the surface plasmon is visible.

o Nanodiode
A nanodiode is comprised of a metal thin film and semiconductor (oxide semiconductor or compound semiconductor), and it refers to the concept that hot electrons emerge on the surface of nanodiode before they are detected by overcoming Schottky energy barrier.

Source - Hellodd.com