Researchers are always looking for new and innovative materials that could improve semiconductor manufacturing. Though many breakthroughs don’t amount to changes in the real world, constant innovation is key to advancing the industry. Scientists from Berkeley Labs and UC Berkeley have recently discovered “multielement ink,” the first high-entropy semiconducting material that can be processed at room temperature. As such, it represents a breakthrough in faster, greener, less heat-intensive semiconductor manufacturing.
Recently reported in Nature, the development of multielement ink will increase sustainability, decrease costs, and lower carbon emissions in chip production. The work was supported by the U.S. Department of Energy’s Office of Science.
“The traditional way of making semiconductor devices is energy-intensive and one of the major sources of carbon emissions,” said Peidong Yang, senior author of the study. “Our new method of making semiconductors could pave the way for a more sustainable semiconductor industry.”
Nearly every electronic device we have come to depend on for modern living incorporates semiconductors. Without them, computers can’t process and store data and LED lightbulbs can’t light our world.
But making these essential chips with traditional methods and materials requires an incredible amount of energy to melt silicon oxide at temperatures around 2700 degrees F. As technology evolves and demand for chips increases, more cost-effective and sustainable manufacturing processes are necessary.
Multielement ink utilizes hard alloys and a softer crystalline halide perovskites material. The former are high-entropy solids comprised of five or more chemical elements. Although silicon requires far more energy to process than conventional high-entropy alloys, the colossal energy input required often prohibits using high-entropy materials for industrial-scale manufacturing.
By contrast, halide perovskites can be processed between room temperature and just 300 degrees F. Berkeley Lab’s Advanced Light Source team leveraged this lower energy requirement of high-entropy halide perovskite single crystals. Using a solution between room temperature 176 degrees F, they created octahedral and cuboctahedral crystals within hours of mixing a solution and precipitating. The resulting multielement ink surprised researchers by remaining stable in ambient air for a period of at least six months.
Yang likened the process to a popular toy building block, “Intuitively, making these semiconductors is like stacking octahedral-shaped molecular ‘LEGOs’ into larger octahedral single crystals.
“Imagining each of these individual molecular LEGOs will emit at different wavelengths, one can in principle design a semiconductor material that would emit an arbitrary color by selecting different molecular octahedral LEGOs,” he added.
Another study author, Maria Fogueras, a former graduate student fellow in the Peidong Yang group at Berkeley Labs and UC Berkeley, discussed another reason why multielement ink makes the manufacturing process so much more sustainable.
“Our high-entropy halide-perovskite semiconductor crystals, with their room-temperature and low-temperature methods, can be incorporated into an electronic device without destroying the other necessary layers, thus allowing for the easier design of electronic devices and more widespread use of high-entropy materials in electronic devices,” Fogueras said.
Multielement ink could have a big impact in chip production and component manufacturing. The research team notes it could be used to make color-tunable LEDs, thermoelectrics for waste heat recovery, and programmable components in optical computing devices that use light to transfer or store data. The team also intends to continue developing sustainable semiconductors for solid-state lighting and displays.
Eventually, Yang believes that octahedral crystals could even carry genetic information, similar to how DNA base pairs carry genetic information. He foresees a time when molecular semiconductors can be coded and decoded for information science applications.
Advancements like this one highlight the possibilities for innovation in the industry. As semiconductor materials continue to evolve, the number of applications will grow. For chipmakers, continuing to pursue these breakthroughs will remain essential in the coming years.