Rice Researchers Link Stacking Faults to Weakened Performance in Ultrathin Materials

Researchers at Rice University have revealed that subtle defects within hexagonal boron nitride (hBN), a key insulator in ultrathin electronics, can significantly weaken material performance and lead to device failure at lower voltages.

The team discovered that these “stacking faults”—misalignments within the material’s atomic structure—trap electrical charges, creating localized weak points. Utilizing cathodoluminescence spectroscopy, they were able to visualize these faults, which remain largely undetectable through conventional microscopy methods. “By showing practical ways to detect when and where these defects form, we help make future devices more reliable and repeatable,” said Hae Yeon Lee, an assistant professor of materials science and nanoengineering at Rice and a corresponding author on the study. This advance offers a pathway toward building more consistent and robust heterostructures for advanced transistors, photodetectors and quantum devices.

Cathodoluminescence Spectroscopy Reveals Hidden hBN Stacking Faults These defects, termed “stacking faults,” manifest as misalignments within the material’s atomic structure and were previously difficult to detect using conventional methods.

The team’s work, recently published in Nano Letters, demonstrates that these faults can trap electrical charges, locally weakening the hBN and increasing the likelihood of premature failure at lower voltages. The investigation focused on hBN flakes routinely peeled from bulk crystals and transferred onto wafers, a process suspected of inducing these structural imperfections. While standard optical and atomic force microscopy revealed seemingly pristine surfaces, the true nature of the material was obscured. To overcome this limitation, the researchers employed cathodoluminescence spectroscopy, a technique utilizing an electron beam to scan the material and analyze the emitted light. “hBN emits deep ultraviolet light that many labs cannot easily excite,” Lee explained, highlighting the specialized equipment at Rice’s Shared Equipment Authority that enabled the analysis. This spectroscopic mapping revealed bright, narrow stacking faults that had previously gone unnoticed, particularly in thicker flakes. These faults aren’t merely cosmetic; they function as “tiny charge pockets and weaken insulation,” causing the hBN to leak electricity at significantly lower voltages than defect-free areas. “A material’s strength, color and electrical behaviors come from the way its atoms are arranged,” Lee said. “However, real materials are not perfect.” The team’s combined approach—electron microscopy, cathodoluminescence mapping, and force-based measurements—offers a practical method for identifying these faults before they compromise device functionality and is also applicable to other layered materials. hBN Defects Lower Dielectric Strength and Device Reliability The team’s investigation revealed that even seemingly pristine hBN flakes, routinely created by peeling from bulk crystals, can harbor these hidden flaws, impacting the consistency of heterostructures used in transistors, photodetectors, and quantum devices. Conventional microscopy techniques proved inadequate for visualizing these defects, prompting the researchers to utilize cathodoluminescence spectroscopy, which scans materials with an electron beam and records emitted light. The resulting emission maps revealed bright, narrow stacking faults previously overlooked, particularly in thicker hBN flakes. These structural changes directly correlate with diminished material performance, as the faults create “tiny charge pockets” that weaken insulation and allow for electrical leakage at lower voltages. This discovery is critical because it explains why identically constructed devices can exhibit varying behaviors, depending on the presence of these fault lines. Funding for the research was provided by the U.S.

Army Research Office, the Japan Society for the Promotion of Science, and the Japan Science and Technology Agency. “By showing practical ways to detect when and where these defects form, we help make future devices more reliable and repeatable,”Hae Yeon Lee, an assistant professor of materials science and nanoengineering at Rice Source: https://news.rice.edu/news/2026/new-technique-spots-hidden-defects-boost-reliability-ultrathin-electronics Tags: Quantum News There is so much happening right now in the field of technology, whether AI or the march of robots. Adrian is an expert on how technology can be transformative, especially frontier technologies. But Quantum occupies a special space. Quite literally a special space. A Hilbert space infact, haha! Here I try to provide some of the news that is considered breaking news in the Quantum Computing and Quantum tech space. Latest Posts by Quantum News: SEALSQ Expands Japan Presence to Support 2035 Quantum Security Mandate February 27, 2026 Quantum eMotion Strengthens Cybersecurity Strategy with SecureKey Platform Acquisition February 27, 2026 QuTech Aims to Overcome Entanglement Decay with New Solid-State Quantum Devices February 27, 2026