Quantum dots/graphene (QDs/GR) composite materials show a distinct synergistic effect between the QDs and graphene, which has aroused vast attention toward their unique characteristics in the last few decades.
A series of zero-dimensional Ge/Si quantum dots (QDs) samples are fabricated by inducing the transformation from the two-dimensional Ge thin film, which is grown by the traditional direct current (DC) magnetron sputtering, via regulating the annealing process. The QD density increases sharply after the post rapid thermal annealing (PRTA). The observations of atomic force microscopy (AFM) and Raman spectroscopy suggest that the good morphology of Ge QDs results from an appropriate thermodynamics and kinetics surrounding shaped by the cooperative interaction of the Ge-Si lattice mismatch, the film's surface temperature, and the difference in thermal expansion coefficients between Ge and Si. The photoluminescence (PL) peaks of Ge QDs are detected in monolayer Ge QDs with ultrahigh density at 17 K. The Metal-Ge/Si QDs-Metal (MGM) photodetector fabricated from the ultrahigh-density QDs sample exhibits a relatively high current gain, absolute photoelectric responsivity, and internal quantum efficiency (IQE). Our results demonstrate that the high-quality Ge QDs with strong light absorption and quantum confinement effect can be realized by modulating DC magnetron sputtering and the PRTA process. This paves the way for realizing silicon-based optoelectronic devices with high performance by the traditional, relatively low-cost, and large-scale production nanomaterial fabricating method.
The Quantum Dots/Graphene (QDs/GR) composites have attracted numerous interests caused by its unique physical and chemical properties in past few decades. The shortages of the single QD and graphene materials could be remedied by the synergistic effects from QDs/GR composite materials; meanwhile, some unique phenomena and superior physical properties were also produced. The QDs/GR composites processed better photocatalytic activities, higher photon capture abilities and excellent optical responsibilities. Therefore, they were widely applied in various techniques. Here, we reviewed and discussed recent research progresses about the QDs/GR composites and focused on their industrial preparation and commercial applications. Among these synthetic methods, ion beam sputtering deposition (IBSD) and molecular beam epitaxy (MBE) were discussed in detail because they could be directly applied in commercial industry for preparing size-tunable quantum dots. In another part, the applications of the QDs/GR composites were also discussed, the advanced physical and chemical properties promoted these composites to have numerous potential for being applied in photodetectors, lithium ion batteries, solar cells, supercapacitors and other devices. The appropriate synthetic method for QDs/GR materials is highly dependent on the requirements of its applications. We firmly believe that the direct synthesis technique of ideal QDs/GR composite for specific applications is a challenge and research emphasis for scientist and engineers in future.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.