Penn State Researchers Uncover Secret Behind Transparent Ceramics' Exceptional Light-Controlling Properties

A new class of ceramics are not only transparent, but they can control light with exceptional efficiency—better than any theories predicted. Now, an advanced theory put forth by researcher at Penn State may explain why this material is so good at light control, which could lead to large-scale manufacturing of these materials for faster, smaller and more energy efficient technologies used in high-speed communications, medical imaging and advanced sensing. To solve the puzzle of why transparent ceramic's electro-optic properties—the ability to change how they bend or transmit light when a voltage is applied—performed far better than predicted, Haixue Yan, reader in materials science and engineering from the Queen Mary University of London, reached out to Zi-Kui Liu, a Penn State professor of materials science and engineering. Liu previously developed an advanced theory of entropy, or the concept that systems trend toward disorder if no energy is applied to keep the chaos at bay. This advanced theory, known aszentropy theory, blendsquantum mechanics, thermodynamics and statistical mechanics into a single predictive framework. Together, along with a team representing multiple institutions across six countries, they solved the mystery and publishedtheir workin theJournal of the American Chemical Society. Ceramics offer major advantages for optical technologies because they are far cheaper to manufacture than single crystals, easier to scale into usable components and allow precise control of composition. However, to function in electro-optic devices, the material must be transparent so that light passes through it smoothly, a longstanding challenge that recent processing advances have finally overcome.