New method improves stability of perovskite quantum dots

May 29, 2017, Ecole Polytechnique Federale de Lausanne
Electron microscopy images of perovskite quantum dots embedded in the protective alumina matrix, and a photograph of the same film stable in water. Credit: R. Buonsanti/EPFL

EPFL scientists have built a new type of inorganic nanocomposite that makes perovskite quantum dot exceptionally stable against air exposure, sunlight, heat, and water.

Quantum dots are nanometer-size, semiconducting materials whose tiny size gives them unique optical properties. Much effort has been put in building from perovskites, which already show much promise for solar panels, LEDs and laser technologies. Their fundamental optoelectronic properties are also very unique and of great interest among the scientific community. However, dots have huge issues with stability against air, heat, light, and water. EPFL scientists have now succeeded in building perovskite quantum dot films with a technique that helps them overcome these weaknesses. The work is published in Angewandte Chemie.

The new approach to stabilize the perovskite quantum dots was developed in the lab of Raffaella Buonsanti at EPFL Valais Wallis. The innovation of this study, developed by Anna Loiudice and PhD student Seryio Saris, lies in a technique called "atomic layer deposition" (ALD), which is commonly used to fabricate ultra-thin films with high uniformity in their structure. The idea was to use ALD to encapsulate the perovskite quantum dots with an amorphous alumina matrix, which acts as a gas and ion diffusion barrier thus making the quantum dots more robust against air, light, heat, and moisture. 

The team used an array of characterization techniques to monitor the nucleation and growth process of the alumina matrix on the quantum dot surface. The process showed that the interaction between the ALD precursor and the dot surface is crucial in order to uniformly coat the dots while preserving their optoelectronic properties. 

"By addressing the stability challenge of perovskite quantum dots, this work is expected to greatly impact the field by enabling fundamental optoelectronic studies, which require the samples to be stable during the measurements, in addition to increase the durability of devices based on this new class of quantum dots," say the authors.

Explore further: An interaction between perovskites and quantum dots could improve LED and solar technologies

More information: Anna Loiudice et al. CsPbBr3 QD/AlOx inorganic nanocomposites with exceptional stability in water, light and heat, Angewandte Chemie International Edition (2017). DOI: 10.1002/anie.201703703

Related Stories

Researchers use quantum dots to manipulate light

August 30, 2016

Leiden physicists have manipulated light with large artificial atoms, so-called quantum dots. Before, this has only been accomplished with actual atoms. It is an important step toward light-based quantum technology. The study ...

Catching more of the sun

April 4, 2016

Combining quantum dots and organic molecules can enable solar cells to capture more of the sun's light.

Recommended for you

Atomic-scale ping-pong

June 20, 2018

New experiments by researchers at the National Graphene Institute at the University of Manchester have shed more light on the gas flow through tiny, angstrom-sized channels with atomically flat walls.

Chameleon-inspired nanolaser changes colors

June 20, 2018

As a chameleon shifts its color from turquoise to pink to orange to green, nature's design principles are at play. Complex nano-mechanics are quietly and effortlessly working to camouflage the lizard's skin to match its environment.

Method could help boost large scale production of graphene

June 19, 2018

The measure by which any conductor is judged is how easily, and speedily, electrons can move through it. On this point, graphene is one of the most promising materials for a breathtaking array of applications. However, its ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.