Valley Hall Effect
The Ministry of Science, ICT and Future Planning (MSIP) announced on July 29 that a research team from Cornell University led by professor Park Ji-woong and professor Paul McEuen presented the possibility of making more energy-efficient semiconductor devices.
As semiconductor devices have been made smaller, the number of devices in electronic equipment has been increasing as well, which leads to an increase in energy consumption. However, a large amount of energy is lost by heat in existing semiconductor devices. That can be seen by cell phones or computers heating up when being used.
To deliver information in a certain direction in the device, particles with high energy should be moved from one end of the device to the other. During that time, some particles with high energy are easily changed into heat energy, which results in an inefficient loss of energy.
The team was able to observe the Valley Hall effect in the MoS2 transistor, where particles with low energy can move in a specific direction without the injection of particles with high energy.
It was also discovered that stable particles with low energy exist in different energy valleys and vibrate in other directions. They put forward the possibility of operating devices without energy loss by making low-energy particles gather in a designated place and then move in a particular direction.
Professor Park said, “I hope that this study will provide a direction in research of new materials as thick as monoatomic elements like MoS2, and bring about an advance in related technology.”
The research was funded by Korea’s MSIP, under the project to develop nano- and materials technology.
The research findings were published online in the June 27 issue of Science, a weekly scientific journal published by the American Association for the Advancement of Science.