Hyper-efficient LED technologies could enable applications from the visible-light LED bulbs in every home, to new displays, to gesture recognition using near-infrared wavelengths.
It’s snack time: you have a plain oatmeal cookie, and a pile of chocolate chips. Both are delicious on their own, but if you can find a way to combine them smoothly, you get the best of both worlds.
Researchers in The Edward S. Rogers Sr. Department of Electrical & Computer Engineering used this insight to invent something totally new: they’ve combined two promising solar cell materials together for the first time, creating a new platform for LED technology.
The team designed a way to embed strongly luminescent nanoparticles called colloidal quantum dots (the chocolate chips) into perovskite (the oatmeal cookie). Perovskites are a family of materials that can be easily manufactured from solution, and that allow electrons to move swiftly through them with minimal loss or capture by defects.
The work is published today in the international journal Nature.
“It’s a pretty novel idea to blend together these two optoelectronic materials, both of which are gaining a lot of traction,” says Xiwen Gong, one of the study’s lead authors and a PhD candidate working with Professor Ted Sargent. “We wanted to take advantage of the benefits of both by combining them seamlessly in a solid-state matrix.”
The result is a black crystal that relies on the perovskite matrix to ‘funnel’ electrons into the quantum dots, which are extremely efficient at converting electricity to light.
“When you try to jam two different crystals together, they often form separate phases without blending smoothly into each other,” says Dr. Riccardo Comin, a post-doctoral fellow in the Sargent Group. “We had to design a new strategy to convince these two components to forget about their differences and to rather intermix into forming a unique crystalline entity.”
The main challenge was making the orientation of the two crystal structures line up, called heteroexpitaxy. To achieve heteroepitaxy, Gong, Comin and their team engineered a way to connect the atomic ‘ends’ of the two crystalline structures so that they aligned smoothly, without defects forming at the seams. “We started by building a nano-scale scaffolding ‘shell’ around the quantum dots in solution, then grew the perovskite crystal around that shell so the two faces aligned,” explained coauthor Dr. Zhijun Ning, who contributed to the work while a post-doctoral fellow at UofT and is now a faculty member at ShanghaiTech.
The resulting heterogeneous material is the basis for a new family of highly energy-efficient near-infrared LEDs. Infrared LEDs can be harnessed for improved night-vision technology, to better biomedical imaging, to high-speed telecommunications.
The Latest on: Quantum dots and perovskite
via Google News
The Latest on: Quantum dots and perovskite
- Perovskite nanowire–block copolymer composites with digitally programmable polarization anisotropyon April 4, 2021 at 5:01 pm
1, A to C). Unlike conventional colloidal semiconducting nanocrystals that typically require a core-shell structure to achieve high photoluminescence (PL) quantum yield, lead halide perovskite ...
- A van der Waals interface that creates in-plane polarization and a spontaneous photovoltaic effecton April 1, 2021 at 11:46 am
1 Quantum-Phase Electronics Center (QPEC ... sets of mirror planes (the rotational axes and mirror planes of each crystal are shown by the circled dots and green lines, respectively, in Fig. 1A).
- Global Quantum Dots Market Report 2021-2031:...on March 26, 2021 at 3:41 pm
For more information about this report visit https://www.researchandmarkets.com/r/6lo3me ...
- ACS nanoon March 25, 2021 at 5:00 pm
Substrate Metabolism-Driven Assembly of High-Quality CdS xSe1- x Quantum Dots in Escherichia coli: Molecular Mechanisms and Bioimaging Application. Using Nanoscopy To Probe the Biological Activity ...
- Ultrastable low-cost colloidal quantum dot microlasers of operative temperature up to 450 Kon March 18, 2021 at 2:06 am
Quantum dot microlasers, as multifunctional optical source components, are of great importance for full-color high-pixel display, miniaturized coherent lighting, and on-chip integrated photonic ...
- Use of perovskite will be a key feature of the next generation of electronic applianceson March 15, 2021 at 6:18 am
made strides in this direction by providing novel insights into the fundamental physics of perovskite quantum dots. An article on the study is published in Science Advances. "We used coherent ...
- Use of perovskite nanomaterials will be a key feature of the next generation of electronic applianceson March 12, 2021 at 11:26 am
made strides in this direction by providing novel insights into the fundamental physics of perovskite quantum dots. An article on the study is published in Science Advances ("Multidimensional coherent ...
- Use of perovskite will be a key feature of the next generation of electronic applianceson March 12, 2021 at 9:59 am
IMAGE: Nanomaterials of perovskite dispersed in hexane and irradiated by laser. Light emission by these materials is intense thanks to resistance to surface defects view more Quantum dots are ...
- Flexible perovskite quantum dot solar cell with 15.1% efficiencyon March 12, 2021 at 4:42 am
perovskite. The scientists added phenyl-C61-butyric acid methyl ester (PCBM), one of the best electron acceptors in organic PV cells, into the CsPbI3 quantum dot layer. The researchers built the ...
- Green Chemistry, Energy and Catalysison February 5, 2021 at 10:04 pm
Charge and spin dynamics in perovskite photovoltaic materials; Electron spin relaxation in III-V semiconductors; Many-body phenomena in semiconductor materials; Solid state quantum information using ...
via Bing News