MIT Engineers’ Major Advance in Creating a New Family of Semiconductor Materials

Epitaxial Growth of Chalcogenide Perovskite Thin Film

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Artist’s conception of the epitaxial development of a chalcogenide perovskite thin movie. The product represents a brand-new household of semiconductors. Credit: Felice Frankel

Ultrastable and made from economical, nontoxic aspects, chalcogenide perovskites might discover applications in solar batteries, lighting, and more.

MIT engineers report developing the very first premium thin movies of a brand-new household of semiconductor products. The accomplishment, which lead scientist Rafael Jaramillo describes as his “white whale” due to the fact that of his fascination in pursuing it throughout the years, has the prospective to effect several fields of innovation if history repeats itself. The capability to develop premium movies of other households of semiconductors caused computer systems, solar batteries, night-vision cams, and more.

When presenting a brand-new product, “the most important scientific breakthroughs are enabled only when we have access to the highest-quality materials available,” states Jaramillo, the Thomas Lord Associate Professor of Materials Science and Engineering at MIT. “Studying materials of low quality often results in false negatives with respect to their scientific interest and technological potential.”

The brand-new household of semiconductors, referred to as chalcogenide perovskites, might have applications in solar batteries and lighting, Jaramillo states. He notes, nevertheless, that “the history of semiconductor research shows that new families of semiconductors are generally enabling in ways that are not predictable.”

New MIT Semiconductor Material

A blue flower is shown in a thin movie of a brand-new semiconductor product established at MIT. The clearness of the reflection affirms to the high quality of the movie. Credit: Photo thanks to Jaramillo et al.

Jaramillo is thrilled about the brand-new products’ prospective due to the fact that they are ultrastable and made from economical, nontoxic aspects. The thin movies his group developed are made up of barium, zirconium, and sulfur in a particular crystal structure, “the prototypical chalcogenide perovskite,” Jaramillo states. “You can make variations by changing the composition. So it is indeed a family of materials, not just a one-off.”

The work has actually been released in the November 3, 2021, concern of Advanced Functional Materials Jaramillo’s coauthors are Ida Sadeghi, a postdoc in the Department of Materials Science and Engineering (DMSE) and very first author of the paper; Kevin Ye, Michael Xu, and Yifei Li, all DMSE college student; and James M. LeBeau, the John Chipman Associate Professor of Materials Science and Engineering at MIT.

A little history

Chalcogenide perovskites were made as early as the 1950 s by French chemists. Similar work was duplicated in the 80 s and early 90 s, however “the idea that these materials would be useful semiconductors didn’t come along until the early 2010s,” Jaramillo states. That’s when Jaramillo and a couple of others– consisting of Jayakanth Ravichandran and Joseph Bennett, all postdocs at the time– individually recognized their capacity.

Today, Ravichandran and Bennett are teachers at the University of Southern California and the University of Maryland Baltimore County, respectively; Jaramillo counts both as pals. Ravichandran, who Jaramillo satisfied when the 2 were postdocs at Harvard University, has actually likewise pursued the objective of developing premium chalcogenide perovskite movies, albeit utilizing a various method. Ravichandran has actually likewise continued with success in this field.

How they did it

Jaramillo and associates utilized a method called molecular beam epitaxy (MBE) to grow their premium movies. The method enables atomic-level control over crystal development, however “it’s very difficult to do and there’s no warranty of success [with a new material],” Jaramillo states. Nevertheless, “the history of semiconductor technology shows the value of developing MBE. That’s why it’s worthwhile to try.”

As its name suggests, MBE basically points beams of particles at a particular plan of atoms on a surface area (“taxy,” as in epitaxy, suggests plan, or orientation). That plan of atoms offers a design template for the beamed particles to grow on. “That’s why epitaxial growth gives you the highest-quality films. The materials know how to grow,” Jaramillo states.

The hard work was more intensified by another element: “the chemicals needed to make chalcogenides are nasty. They stink, and they can gum up equipment,” Jaramillo states. MBE happens in a vacuum chamber, and Jaramillo remembers the hesitation of individuals to permit his group access to their chambers.

Says Hideo Hosono, a teacher at the Tokyo Institute of Technology who was not associated with the work, “the thin movies [created by Jaramillo et al.] reveal a mirror-smooth image as an outcome of an atomically flat surface area, and exceptional quality. We might prepare for the awareness of gadget fabrication such as solar batteries and green LEDs as the next publications.”

What’s next?

“It’s almost a question of what isn’t next,” Jaramillo states. “Now that we can make these high-quality materials, there’s almost no measurement we could do that wouldn’t be interesting to a wide community of people.” For now, his group is concentrating on 2 locations: checking out basic concerns to acquire a much better understanding of the products, and incorporating them into solar batteries. In among his postdoctoral consultations prior to signing up with the MIT professors, Jaramillo dealt with solar batteries, so “I’ll be able to leverage a lot of what I did then.”

Chalcogenide perovskites are not the sole focus of Jaramillo’s laboratory at MIT. “But this is definitely the project we’re proudest of because it’s taken the most effort and the most delayed gratification.”

Reference: “Making BaZrS 3 Chalcogenide Perovskite Thin Films by Molecular Beam Epitaxy” by Ida Sadeghi, Kevin Ye, Michael Xu, Yifei Li, James M. LeBeau and Rafael Jaramillo, 16 August 2021, Advanced Functional Materials
DOI: 10.1002/ adfm.202105563

This work was supported by the National Science Foundation, the Office of Naval Research, the Skolkovo Institute of Science and Technology as part of the MIT-Skoltech Next Generation Program, and the Air Force Office of Scientific Research.

Facilities handled by the MIT Materials Research Laboratory and by MIT.nano were utilized for part of the work.