Physics World names UH research among top 10 breakthroughs for 2022

Physics World Names Groundbreaking Work of University of Houston Researchers Demonstrating Cubic Boron Arsenide as “One of the Best Semiconductors Known to Science” on Top 10 Breakthroughs for 2022 List included.

Two independent teams, one led by Zhifeng Ren of UH and Gang Chen of the Massachusetts Institute of Technology and another led by Ren and Jiming Bao of UH and Xinfeng Liu of China’s National Center for Nanoscience and Technology, tested the cube experimentally. Did. High carrier mobility in boron arsenide crystals for both electrons and holes – two ways charge is transported in semiconductor materials.

The crystal, which has been grown in Ren’s lab since 2015 from boron and arsenic, two relatively common mineral elements, showed in 2018 much higher thermal conductivity than conventional semiconductors. I was.

This is important because semiconductors require current to be carried through both electrons and holes, but most known materials offer high mobility for only one type of carrier. The overall efficiency of the semiconductor is determined by the lower value. This makes cubic boron arsenide crystals very efficient and much closer to practical use thanks to this cutting-edge research.

Ren, director of UH’s Texas Center for Superconductivity, said the research is important for a variety of electronic and optical applications, such as the advances that followed the advent of silicon wafers, which are widely used in all kinds of electronics. It is said that it has a meaning.

“The potential for this material is tremendous,” said Ren, who is also MD Anderson’s chief professor of physics. Work is underway to consistently produce larger crystals with uniform properties, but the results could have an even greater impact on the field than silicon wafers, he said.

How to proceed with research

The first step was to grow better crystals in Ren’s lab. Next, according to Bao, a professor of electrical engineering and principal investigator at the Texas Center for Superconductivity, the researchers used laser pulses to excite carriers in the sample and monitor their diffusion, and in the process, Cubic boron arsenide and quartz and most semiconductor materials. For example, in silicon, electrons travel about four times faster than holes.

“Both holes and electrons move faster in this case,” he said, adding that both electrons and holes exhibit unusually high mobility, improving the overall performance of the material.

Bao attributes the highest readings to “hot electrons.” Hot electrons sustain the heat or energy produced by a laser pulse longer than most other materials. The same was true for holes in the material, said Bao.

The structure of the cubic arsenide arsenic crystal makes it difficult for the charge carriers to cool down and retain heat for a long time, resulting in high mobility. Measurements were performed in UH ​​and MIT labs using different methods.

Read about Physics World’s top 10 breakthroughs for 2022.