Article last updated on: Nov 30, 2020

Perovskites are materials that share a crystal structure similar to the mineral called perovskite, which consists of calcium titanium oxide (CaTiO3).

Solutions of all-inorganic perovskite quantum dots, showing intense photoluminescence when illuminated with UV light

Depending on which atoms/molecules are used in the structure, perovskites can possess an impressive array of interesting properties including superconductivity, ferroelectricity, charge ordering, spin dependent transport and much more. Perovskites therefore hold exciting opportunities for physicists, chemists and material scientists.

Quantum dots (QDs), sometimes referred to as semiconducting nanocrystals (NCs), are miniscule particles of a semiconducting material with diameters in the range of 2-10 nanometers (10-50 atoms). Quantum dots have properties labeled as intermediate between bulk semiconductors and discrete atoms or molecules. Their optoelectronic properties change as a function of both size and shape. QDs demonstrate optical and electronic properties different from those of larger particles. In fact, QDs tend to exhibit quantum size effects in their optical and electronic properties, like tunable and efficient photoluminescence (PL), with narrow emission and photochemical stability. This is why QDs have been incorporated as active elements in a wide variety of devices and applications, some of which are already commercially available, such as QD-based displays.

Perovskite quantum dots (PQDs) are a class of quantum dots based on perovskite materials. While these are relatively new, they have already been shown to have properties matching or surpassing those of the metal chalcogenide QDs: they are more tolerant to defects and have excellent photoluminescence quantum yields and high colour purity. Such attractive properties are extremely suited for electronic and optoelectronic applications and so perovskite quantum dots have significant potential for real world applications, some of which are already emerging, including LED displays and quantum dot solar cells.

The latest Perovskite QD news:

A new approach could result in efficient and stable perovskite QLEDs

Researchers at the College of Materials Science and Engineering at Nanjing University of Science and Technology in China have developed a technique that greatly enhances perovskite QLEDs' performance and stability compared to single interface processing.

New passivation approach yields efficient QDLEDs imageThe structure of QLED based on QD films passivated without (b) and with passivation (c). Image from Nature Communications

The team proposed a bilateral passivation strategy through passivating the top and bottom interface of the QD film with organic molecules.

Researchers use perovskite QDs to design a device that mimics brain cells used for human vision

University of Central Florida researchers are helping to close the gap separating human and machine minds, using a technology based on perovskite quantum dots. In a recent study, a UCF research team showed that by combining two promising nanomaterials into a new superstructure, they could create a nanoscale device that mimics the neural pathways of brain cells used for human vision.

"This is a baby step toward developing neuromorphic computers, which are computer processors that can simultaneously process and memorize information," said Jayan Thomas, an associate professor in UCF's NanoScience Technology Center and Department of Materials Science and Engineering. "This can reduce the processing time as well as the energy required for processing. At some time in the future, this invention may help to make robots that can think like humans."

CSoT demonstrates a 6.6" 384x300 OLED display that uses perovskite quantum dots for color conversion

China-based display maker China Star (CSoT, a subsidiary of TCL) demonstrated a 6.6-inch 384x300 OLED display that uses perovskite quantum dots as a color conversion film.

CSoT is using blue OLED emitter materials, and a perovskite layer to up-convert the color to green (this is a monochrome prototype - evidently a very early prototype). CSoT brands its perovskite-OLEDs as PE-OLED and we believe this is the first time a perovskite-enhanced display has been publicly demonstrated.