Recently, the research groups led by Prof. Zhihua Ni and Prof. Junpeng Lü from Southeast University have made significant progress in the study of photoluminescence blinking mechanisms at two-dimensional/three-dimensional (2D/3D) heterointerfaces. For the first time, the team discovered and elucidated the mechanism of B-type blinking at 2D/3D heterojunction interfaces, filling a critical gap in the study of fluorescence blinking in two-dimensional materials. This work provides important scientific insights into exciton dynamics and interfacial energy regulation in 2D systems. The results were published in Advanced Materials under the title “Origin of B-Type Blinking at 2D/3D Heterojunction Interfaces”.
Photoluminescence blinking, a phenomenon of random fluctuations in light emission, is widely observed in nanoscale materials and serves as a key probe of defect states and charge carrier dynamics. While such behavior has been extensively studied in quantum dots and nanowires, its manifestation in two-dimensional materials has remained poorly understood. Until now, only one type of blinking (A-type) had been observed in 2D systems, and even its origin was still under debate.
Using a model WS2/Si heterostructure, the Southeast University team combined advanced techniques, including fluorescence lifetime–intensity distribution (FLID) analysis, temperature-dependent spectroscopy, and transient absorption measurements, to uncover a new blinking mode. Unlike conventional blinking, the newly identified B-type blinking exhibits strong fluctuations in emission intensity while maintaining a nearly constant fluorescence lifetime, which is a signature not reported before in 2D materials or their heterostructures.
The researchers traced this phenomenon to a dynamic competition between A excitons and localized excitons. Their measurements revealed a clear anticorrelation between the two emission channels, indicating that the blinking originates from fluctuating population distributions between these states. Crucially, the study shows that Förster resonance energy transfer (FRET) at the WS2/Si interface plays a central role. By modulating the density of localized excitons and preventing trap-state saturation, interfacial energy transfer sustains the blinking behavior over time.
The team proposes a new physical model based on exciton competition and interfacial energy transfer, providing a unified framework for understanding interactions between excitons and defects in 2D materials. Beyond fundamental science, the findings have direct implications for the design of high-performance optoelectronic devices. Improved control over interfacial processes and defect states could enable more stable light emission, benefiting applications in photodetectors, integrated photonic systems, and emerging light sources.
Southeast University served as the sole corresponding institution. The study was conducted by researchers from the university’s Schools of Electronic Science and Engineering and Physics. Dr. Tao Zhou and Associate Professor Dongyang Wan contributed as co-first authors. This research was supported by the National Key R&D Program of China, the National Natural Science Foundation of China, the Jiangsu Provincial Frontier Leading Technology Basic Research Program, the Jiangsu Provincial Major Science and Technology Program, as well as the Key Laboratory of Quantum Materials and Information Devices (Ministry of Education) at Southeast University and the Start-up Funding for New Faculty Members.
Link:https://doi.org/10.1002/adma.202510833
