Recently, Professor Hu Yihua’s team from the College of Electronic Engineering of National University of Defense Technology (NUDT) made a significant breakthrough in the field of metal quantum dots (QDs). The team successfully developed a novel core-shell heterostructure quantum dot (AgNC@AgAux QDs) with a remarkable photoluminescence (PL) enhancement of 94.06 times and a quantum yield improvement of 32.40 times. This is accomplished through electron injection and the strong localized electric field induced by surface plasmon effects. This groundbreaking research, titled “Synergistic Enhancement of Fluorescence through Plasmon Resonance and Interfacial Charge Transfer by AgNC@AgAux Core-Shell Quantum Dots” , was published in the internationally renowned journal Advanced Materials (Impact Factor: 27.4, https://doi.org/10.1002/adma.202415388).
Figure 1. The electron transfer patterns of QDs revealed by density functional theory and finite element analysis.
QDs, often referred to as “artificial atoms”, are nanostructures that confine excitons in three-dimensional space. Due to their unique photoelectric properties, they hold immense potential in applications such as optical imaging, optical communication, biomedical detection and so on. However, the limited quantum yield and PL intensity of traditional QDs hindered their practical performance. Professor Hu Yihua’s team innovatively designed a core-shell structure, rapidly injecting hot electrons originating from the Ag core and induced by surface plasmon resonance into the conduction band. This process overcame the interfacial energy barrier at the M critical point, significantly enhancing the PL performance of the quantum dots and improving the quantum yield of material.
Figure 2. The femtosecond transient absorption spectra electron transfer patterns of QDs.
This novel quantum dots can be fabricated into optoelectronic devices such as light-emitting grating, optical storage chips and so on. They also enable the specific detection of heavy metal Cu²⁺ ions in solutions. This research provides valuable insights for constructing complex functional structures at the atomic scale, paving the way for advancements in optoelectronic devices, optical imaging, and the detection of heavy metal ions. Additionally, specialized smokescreens developed based on these QDs may have the potential applications in non-line-of-sight scattering optical communication in complex media environments, enabling rapid deployment of communication links.
This work was led by Professor Hu Yihua’s team, with Ph.D. student Chen Youlong as the first author. Professor Hu Yihua, Assistant Research Fellow Zhang Yushuang, and Academician Chu Junhao from the Shanghai Institute of Technical Physics of Chinese Academy of Sciences are the co-corresponding authors. In recent years, this team has achieved prolific research outcomes in the fields of photoelectric detection and electronic countermeasures, publishing six monographs and over 400 papers in prestigious journals such as Advanced Materials, Photonics Research, IEEE Transactions on Geoscience and Remote Sensing and so on. This latest breakthrough further enriches their research in quantum technology and its practical applications.
Written by: Wang Zongyi, Luo Yalan