U.S. manufactures transistors that do not use semiconductors

For the first time, American scientists used nano-sized insulator boron nitride and gold quantum dots to realize the quantum tunneling effect and created transistors without semiconductors. The results are expected to open up new eras of electronic devices.

For decades, electronic devices have become smaller and smaller, and scientists are now able to integrate millions of semiconductors on a single silicon chip. Ye Yuejin, a physicist at the Michigan Institute of Technology who is the leader of the study, said: “According to the current technological development situation, the transistor cannot be made smaller in 10 to 20 years. There is another semiconductor. Congenitally deficient, which will waste a lot of energy in the form of heat."

Scientists try to use different materials and semiconductor design methods to solve the above problems, but all are related to semiconductors such as silicon. In 2007, Ye Yuejin began another way to create transistors without semiconductors. Ye Yuejin said: "My idea is to use nano-scale insulators and place nano-metals on top of them to make transistors. We chose boron nitride carbon nanotubes (BNNTs) as pedestals." Later, they used lasers to make diameters. Three nanometer-wide gold quantum dots (QDs) were placed on top of boron nitride nanotubes to form quantum dots—boron nitride carbon nanotubes (QDs-BNNTs). For gold quantum dots, boron nitride nanotubes are the perfect pedestal. They are small, controllable, and consistent in diameter. They are also insulated and can also limit the size of quantum dots on them.

Researchers have teamed up with ORNL researchers to energize the quantum dots, the electrodes on both sides of the boron nitride nanotubes, at room temperature. The interesting thing happened: electrons jump from one quantum dot to another very precisely, which is the quantum tunneling effect. Ye Yuejin said: "The stability of this equipment is very good."

Ye Yuejin's team used this equipment to create a type of transistor in which there was no semiconductor "silhouette." When a sufficient voltage is applied, it will open to the conductive state; when the voltage is low or closed, it will return to its natural insulator state. Moreover, this device does not have a "slippery fish": no electrons from the gold quantum dot flee into the insulated boron nitride carbon nanotubes, so the tunnel will remain cold. Silicon often encounters leakage, which causes a large amount of energy in electronic devices to be wasted in the form of heat.

John Yaschchacker, a physicist at Michigan Technological University, has developed a theoretical framework for the new transistor. He said that other scientists had previously used quantum tunneling to make transistors, but these devices only work at liquid helium temperature (4.2K), and new equipment can work at room temperature.

The secret of Ye Yuejin’s gold-nanotube device is “small”: it is only 1 micron long and 20 nanometers wide. Yashkak explained: “The width of this gold island must be at the nanometer level so that electrons can be controlled at room temperature. If they are too large, there are many electrons that can flow on it. In theory, when the electrodes are between At a distance of a fraction of a micron, these tunnels can be as small as near zero."