April 26, 2024

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

By Elizabeth A. Thomson, MIT Materials Lab
November 12, 2021

Jaramillo is excited about the new products possible since they are ultrastable and made of inexpensive, nontoxic components. The thin movies his team created are made up of barium, zirconium, and sulfur in a specific crystal structure, “the prototypical chalcogenide perovskite,” Jaramillo states. Comparable work was duplicated in the 80s and early 90s, but “the idea that these products would be beneficial semiconductors didnt come along until the early 2010s,” Jaramillo states. Ravichandran, who Jaramillo met when the 2 were postdocs at Harvard University, has likewise pursued the goal of developing top quality chalcogenide perovskite movies, albeit using a different method. The materials know how to grow,” Jaramillo states.

The brand-new household of semiconductors, referred to as chalcogenide perovskites, might have applications in solar batteries and lighting, Jaramillo says. He notes, nevertheless, that “the history of semiconductor research study reveals that new families of semiconductors are generally allowing in methods that are not predictable.”
A blue flower is shown in a thin movie of a brand-new semiconductor product established at MIT. The clearness of the reflection testifies to the high quality of the movie. Credit: Photo thanks to Jaramillo et al
. Jaramillo is excited about the new products potential due to the fact that they are ultrastable and made of affordable, nontoxic elements. The thin films his group created are made up of barium, zirconium, and sulfur in a particular crystal structure, “the prototypical chalcogenide perovskite,” Jaramillo says. “You can make variations by altering the composition. So it is certainly a household of products, not just a one-off.”
The work has been published in the November 3, 2021, concern of Advanced Functional Materials. Jaramillos coauthors are Ida Sadeghi, a postdoc in the Department of Materials Science and Engineering (DMSE) and first author of the paper; Kevin Ye, Michael Xu, and Yifei Li, all DMSE graduate trainees; 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 1950s by French chemists. Similar work was repeated in the 80s and early 90s, but “the concept that these products would be beneficial semiconductors didnt occurred until the early 2010s,” Jaramillo says. Thats when Jaramillo and a few others– including Jayakanth Ravichandran and Joseph Bennett, all postdocs at the time– independently identified their potential.
Today, Ravichandran and Bennett are professors at the University of Southern California and the University of Maryland Baltimore County, respectively; Jaramillo counts both as friends. Ravichandran, who Jaramillo met when the two were postdocs at Harvard University, has actually likewise pursued the objective of producing top quality chalcogenide perovskite films, albeit utilizing a different technique. Ravichandran has actually likewise continued with success in this field.
How they did it
Jaramillo and coworkers utilized a method called molecular beam epitaxy (MBE) to grow their high-quality movies. The strategy enables atomic-level control over crystal development, however “its extremely hard to do and theres no warranty of success [with a new product],” Jaramillo says. Nonetheless, “the history of semiconductor innovation shows the worth of establishing MBE. Thats why its worthwhile to attempt.”
“Thats why epitaxial growth provides you the highest-quality movies. The materials understand how to grow,” Jaramillo states.
The tough work was more intensified by another aspect: “the chemicals needed to make chalcogenides are nasty. They stink, and they can gum up devices,” Jaramillo states. MBE happens in a vacuum chamber, and Jaramillo remembers the hesitation of people to permit his group access to their chambers.
We may prepare for the awareness of device fabrication such as solar cells and green LEDs as the next publications.”
Whats next?
” Its nearly a concern of what isnt next,” Jaramillo states. In one of his postdoctoral consultations prior to signing up with the MIT professors, Jaramillo worked on solar cells, so “Ill be able to take advantage of a lot of what I did then.”
Chalcogenide perovskites are not the sole focus of Jaramillos laboratory at MIT. “But this is certainly the task were proudest of due to the fact that its taken the most effort and the most postponed satisfaction.”
Referral: “Making BaZrS3 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 used for part of the work.

Artists conception of the epitaxial growth of a chalcogenide perovskite thin film. The material represents a brand-new household of semiconductors. Credit: Felice Frankel
Ultrastable and made from low-cost, nontoxic elements, chalcogenide perovskites might discover applications in solar batteries, lighting, and more.
MIT engineers report developing the first top quality thin movies of a brand-new family of semiconductor materials. The accomplishment, which lead scientist Rafael Jaramillo refers to as his “white whale” because of his fascination in pursuing it throughout the years, has the prospective to impact multiple fields of technology if history repeats itself. The capability to create premium movies of other families of semiconductors led to computer systems, solar batteries, night-vision video cameras, and more.
When introducing a new product, “the most essential clinical breakthroughs are enabled only when we have access to the highest-quality products offered,” says Jaramillo, the Thomas Lord Associate Professor of Materials Science and Engineering at MIT. “Studying products of poor quality often results in incorrect negatives with respect to their clinical interest and technological potential.”