Solution-processed transitional metal chalcogenide (TMD) nanosheets exhibited limited light-absorption and low quantum efficiencies because of their atomic-scale thicknesses and large specific surface area accompanied with a high density of surface defects, which restricted their applications in optoelectronics.
Xiao Huang and co-workers, who were devoted to the development for the synthesis of 2D nanomaterial-based hybrids and their applications in sensing and energy-related applications, from Nanjing Tech University, demonstrated a facile wet-chemical method to directly grow organic-inorganic hybrid perovskite (MAPbBr3, MA = CH3NH3+) NCs on surfaces of dispersible MoS2 nanosheets, recently published in Science China Materials (doi: 10.1007/s40843-018-9274-y).
Recently, TMDs and organic-inorganic hybrid perovskites have been combined into heterostructures, with the aim to marrying their good electronic and optical properties. Huang, the leader of the research group, tells us "Such heterojunctions have been realized mostly via solid-state methods typically involving chemical vapor deposition (CVD), mechanical exfoliation and/or dry transfer, which are difficult to scale-up for practical applications."
She emphasized, "Direct growth of perovskite crystals on dispersible 2D materials in solution enables the scalable production of solution-processible hetero-structures, but has not been realized, because the precipitation of perovskite crystals usually requires a non-polar solvent, which is incompatible with most solvation conditions for 2D materials."
By facile tuning the solvation conditions, cubic-phased MAPbBr3 (MA = CH3NH3+) nanocrystals were epitaxially deposited on trigonal/hexagonal-phased MoS2 nanosheets in solution. In spite of the mismatched lattice symmetry between the square MAPbBr3 (001) overlayer and the hexagonal MoS2 (001) substrate, two different aligning directions with lattice mismatch of as small as 1% were observed based on the domain-matching epitaxy.
This was realized most likely due to the flexible nature and absence of surface dangling bonds of MoS2 nanosheets. The formation of the epitaxial interface affords an effective energy transfer from MAPbBr3 to MoS2.
The dispersible MAPbBr3/MoS2 epitaxial heterostructures can be directly drop-casted between two graphite electrodes drawn by pencil on a piece of paper to form a photodetector with simple configuration, and demonstrated the much improved performance compared to using MoS2 or MAPbBr3 alone due to the improved light absorption and enhanced energy transfer.
In addition to the improved energy transfer and light absorption, the use of MoS2 nanosheets provided flexible and continuous substrates to connect the otherwise discrete MAPbBr3 nanocrystals and achieved the better film forming ability.
Prof. Xiao Huang tells us "The scalable preparation of heterostructures based on organic-inorganic hybrid perovskites and 2D materials via solution-phase epitaxy may bring about more opportunities for expanding their optoelectronic applications."
This research was funded by the National Natural Science Foundation of China (51322202), and the Young 1000 Talents Global Recruitment Program of China.
See the article: Zhipeng Zhang, Fangfang Sun, Zhaohua Zhu, Jie Dai, Kai Gao, Qi Wei, Xiaotong Shi, Qian Sun, Yan Yan, Hai Li, Haidong Yu, Guichuan Xing, Xiao Huang, Wei Huang. "Unconventional solution-phase epitaxial growth of organic-inorganic hybrid perovskite nanocrystals on metal sulfide nanosheets."
Sci. China Mater. 2018, doi: 10.1007/s40843-018-9274-y.
YAN Bei | EurekAlert!
Understanding high efficiency of deep ultraviolet LEDs
22.02.2019 | Tohoku University
Large-scale window material developed for PM2.5 capture and light tuning
18.02.2019 | University of Science and Technology of China
An international research team including astronomers from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has combined radio telescopes from five continents to prove the existence of a narrow stream of material, a so-called jet, emerging from the only gravitational wave event involving two neutron stars observed so far. With its high sensitivity and excellent performance, the 100-m radio telescope in Effelsberg played an important role in the observations.
In August 2017, two neutron stars were observed colliding, producing gravitational waves that were detected by the American LIGO and European Virgo detectors....
Up to now, OLEDs have been used exclusively as a novel lighting technology for use in luminaires and lamps. However, flexible organic technology can offer much more: as an active lighting surface, it can be combined with a wide variety of materials, not just to modify but to revolutionize the functionality and design of countless existing products. To exemplify this, the Fraunhofer FEP together with the company EMDE development of light GmbH will be presenting hybrid flexible OLEDs integrated into textile designs within the EU-funded project PI-SCALE for the first time at LOPEC (March 19-21, 2019 in Munich, Germany) as examples of some of the many possible applications.
The Fraunhofer FEP, a provider of research and development services in the field of organic electronics, has long been involved in the development of...
For the first time, an international team of scientists based in Regensburg, Germany, has recorded the orbitals of single molecules in different charge states in a novel type of microscopy. The research findings are published under the title “Mapping orbital changes upon electron transfer with tunneling microscopy on insulators” in the prestigious journal “Nature”.
The building blocks of matter surrounding us are atoms and molecules. The properties of that matter, however, are often not set by these building blocks...
Scientists at the University of Konstanz identify fierce competition between the human immune system and bacterial pathogens
Cell biologists from the University of Konstanz shed light on a recent evolutionary process in the human immune system and publish their findings in the...
Laser physicists have taken snapshots of carbon molecules C₆₀ showing how they transform in intense infrared light
When carbon molecules C₆₀ are exposed to an intense infrared light, they change their ball-like structure to a more elongated version. This has now been...
11.02.2019 | Event News
30.01.2019 | Event News
16.01.2019 | Event News
22.02.2019 | Physics and Astronomy
22.02.2019 | Materials Sciences
22.02.2019 | Life Sciences