Ultra-thin electronics to become more efficient with method to spot defects

Researchers at Rice University have developed a new technique to detect hidden defects in ultra-thin electronics made from stacked two-dimensional (2D) materials, such as advanced transistors, photodetectors, and quantum devices. These defects, specifically stacking faults in hexagonal boron nitride (hBN)—a common 2D insulator valued for its atomic flatness and chemical stability—can trap electrical charges and locally weaken the material. This weakening causes devices to fail at lower voltages, leading to inconsistent performance even among devices fabricated identically. The team used cathodoluminescence spectroscopy, which involves scanning the material with an electron beam and recording emitted light, to reveal these narrow stacking faults that conventional optical or atomic force microscopy methods miss. They found that these defects form more readily in thicker hBN flakes and act as tiny charge pockets, causing electrical leakage along the faults. By combining electron microscopy, cathodoluminescence mapping, and force-based measurements, the researchers established a practical method