Tiny semiconducting crystals show promise for solar cell architectures and light-emitting devices.
Ames Laboratory scientists discovered semiconducting nanocrystals that function not only as stellar light-to-energy converters but also as stable light emitters.
Honing methods to fine-tune optimal characteristics of materials that convert light to energy may lead to more efficient materials, as performance depends critically on composition, crystallinity, and morphology. These perovskites could be used in the construction of new solar cell architectures, as well as for light-emitting devices and single particle imaging and tracking.
Perovskite materials, such as CH3NH3PbX3 (X = I, Br), are known to display intriguing electronic, light-emitting, and chemical properties. Researchers at the Ames Laboratory synthesized a series of perovskite nanocrystals with different morphologies (i.e., dots, rods, wires, plates, and sheets) by using different solvents and capping ligands. The Ames Laboratory team tested the nanocrystals to explore their morphology, growth, properties, and stability under various conditions.
Characterization studies of photoluminescence, like that seen with glow-in-the-dark paint, found that the rods and wires showed higher photoluminescence and longer photoluminescence lifetimes compared to other shapes. Perovskite nanocrystals with bromine were found to be particularly unstable when exposed to an electron beam during transmission electron microscopy analysis, “melting” to form smaller dot-like particles of unknown composition. Further optical studies revealed that the nanocrystals with iodine are shape-correlated stable light emitters at room temperature.
This research is supported by the U.S. Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences, Separations and Analysis Program through the Ames Laboratory. The Ames Laboratory is operated for DOE by Iowa State. This work was performed, in part (AFM/PL), at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the DOE Office of Science. Los Alamos National Laboratory is operated by Los Alamos National Security, LLC, for the National Nuclear Security Administration of DOE.
F. Zhu, L. Men, Y. Guo, Q. Zhu, U. Bhattacharjee, P.M. Goodwin, J.W. Petrich, E.A. Smith, J. Vela, “Shape evolution and single particle luminescence of organometal halide perovskite nanocrystals.” ACS Nano, 9, 2948 (2015). [DOI: 10.1021/nn507020s]
Kristin Manke | newswise
Nagoya physicists resolve long-standing mystery of structure-less transition
21.08.2017 | Nagoya University
Scientists from the MSU studied new liquid-crystalline photochrom
21.08.2017 | Lomonosov Moscow State University
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
21.08.2017 | Materials Sciences
21.08.2017 | Health and Medicine
21.08.2017 | Materials Sciences