Electronic component capable of tolerance to super high temperature

Many industrial areas require electronic devices to be able to work in harsh environments, including over 200 degrees Celsius. In the aerospace industry, the electronic devices and sensors required for drilling operations in the oil and gas industry are required to work in a high temperature environment. Although the traditional cooling system can help the electronic devices at high temperature, normal work, but in some areas, cooling method does not apply, or said to system stability and cost decreased, more people want to electronic equipment can work under the condition of high temperature. However, the normal operation of the high temperature of the transistor and electronic circuits is very small.

Recently, the from a group of researchers at the University of California, riverside, and Rensselaer Polytechnic Institute found a scientific name for MoS2, semiconductor materials are expected to be used to make under the condition of high temperature thin - film transistor. In this week published in an article in the American Physical Society published in the Journal of Applied Physics, researchers reported molybdenum disulfide thin - film transistor fabrication process and functional properties at high temperature, showing the material can be used for making resistance to high temperature electronic components of the potential.

"Our study show that the thin - film transistor at least 500 Kelvin (220 degrees Celsius) high temperature can still work normally," said professor at the University of California, riverside, Department of electronic engineering, and the research group leader Alexander Balandin. "And the transistor after two months still show stable working performance, suggesting that molybdenum disulfide thin - film transistor has the potential to be used in resistance to high temperature electronic devices and sensors in."

Molybdenite ore MoS2 and the ore large exists in nature, usually is used as lubricant additives. By means of chemical gas phase deposition method, obtained MoS2 can be used to make flexible thin - film transistor -- such as a tap can control the movement of the electron and current components.

According to Balandin said, MoS2 belongs to family of van der Waals materials and its structure characteristics is a crystal structure of atomic layer between the binding force is very weak (such binding force is also known as van der Waals force). The weak interaction between the layer and the layer allows the material to be stripped off layer by layer, which is similar to that of a single atomic layer of graphite, which can be stripped from the whole piece of graphite. The layered structure also shows that high quality ultrathin layers can be obtained by chemical vapor deposition in industrial production.

"Although traditional wide bandgap semiconductors such as SiC or Gan made devices can also be extended to under the condition of high temperature operation, but these materials due to the high cost and not applicable to industrial mass production," said Balandin. "The single-layer MoS2 to bandwidth is 1.9 EV, larger than SiC or Gan, more suitable for industrial production. Wide band means that the element can be quickly turned on and off, which is a very important characteristic of the transistor.

Is a kind of new material concerned

In recent years, molybdenum disulfide in instrument manufacture and application caused the widespread concern. Balandin team for the first time on the potential applications of the materials in high temperature electronic equipment.

      In the high temperature experiment, Balandin research group in a clean laboratory using standard lithographic techniques the MoS2 transistor fabricated on silicon substrate. Some transistors have only a few atomic layers of thickness (e.g., 1-3), while others have a layer of thickness (15-18). Balandin said their experiments showed that the relatively thick layer of the sheet has a more temperature stability, and show a higher carrier mobility with the increase of temperature.

      By measuring the DC, namely in the system continued for a period of time stable loading current and voltage, the researchers study the temperature from 300 Kelvin rise to 500 Kelvin transistor current voltage characteristic curve that functional properties.

      "Carrier mobility and threshold voltage will be decreased with the increase of the temperature," said Balandin. "The decrease of the carrier mobility will lead to the decrease of the current through the component channel, and the threshold voltage will cause the increase of the current. Therefore, the specific performance of the current with the increase of temperature depends on the carrier mobility and the threshold voltage at the same time reduce the interaction of the results."