Perovskite-based quantum dots - a guest post by Ossila

What are Quantum Dots?

Quantum dots (QDs) are semiconducting nanocrystals that are very small – only a few nanometres in size. In display technologies, the most common types of QDs used are composed of a metal chalcogenide core. These QDs have the chemical formula XY – where X is a metal and Y is sulfur, tellurium or selenium (e.g. CdTe, CdSe, ZnS) – which is encased with the shell of a second semiconductor (e.g. CdSe/CdS). Their tiny dimensions mean that charge carriers are confined in close proximity, which gives QDs optical and electronic properties that are substantially different from those of large semiconductor crystals.

QLEDs vs OLEDs

In particular, QDs have enhanced light absorption and emission, making them particularly suitable for display technologies. Metal chalcogenide quantum dots (MCQDs) have already made it into commercial products – most notably, in Samsung’s QLED television range. Here, a blue LED backlight excites a layer of quantum dots on an LCD panel, causing them to emit light. The color of light emitted by the quantum dots depends on their size – with small dots emitting blue light, and progressively larger dots emitting green, yellow, orange, and red light.

Ossila QD structure imageLeft: Core-shell quantum dot structure. Right: The size of the dot defines the color of light that the dot emits. (Source: Ossila.com)

Perovskite-Info interviews Ossila's lead perovskite scientist

UK-based Ossila provides components, equipment and materials to enable faster and smarter organic electronics research and discovery. Ossila provides both materials and equipment for perovskite researchers, and the company's lead perovskite scientist, Dr. Jonathan Griffin, was kind enough to answer a few questions we had for him.

Perovskite crystals (Ossila)Thanks to improved knowledge about salt-solvent interactions, single crystals of perovskites can now be grown. Pictured above are several single-crystal MAPbBr perovskites, alongside the seed crystals used to grow these crystals

Dr. Griffin holds nearly a decade of experience working in organic photovoltaic research and over 5 years of working with perovskites. At Ossila, Jonathan works on technical support for several material ranges, including perovskites, organic photovoltaics, graphene and other 2-D materials. He is also involved in the development of new test equipment and product ranges. Prior to this, he worked in a postdoctoral research position at the University of Sheffield.

Q: Thank you for your time Dr. Griffin. Can you detail for us Ossila's perovskite product range in general?