Perovskite-Info: the perovskite experts

Perovskite-Info is a news hub and knowledge center born out of keen interest in the wide range of perovskite materials.

Perovskites are a class of materials that share a similar structure, which display a myriad of exciting properties like superconductivity, magnetoresistance and more. These easily synthesized materials are considered the future of solar cells, as their distinctive structure makes them perfect for enabling low-cost, efficient photovoltaics. They are also predicted to play a role in next-gen electric vehicle batteries, sensors, lasers and much more.

Recent perovskite News

Researchers create a field-effect transistor using a single-crystal, “paint-on” perovskite

An international team of researchers, led by Aram Amassian at North Carolina State University, has demonstrated the construction of field-effect transistors using a single crystal, hybrid perovskite semiconductor.

Researchers create a field-effect transistor using a single-crystal, “paint-on” perovskite image

While the design of perovskite solar cells has matured to the point of near-commercialization, making hybrid perovskites function as field-effect transistors has been more of a challenge. This is in part due to the fact that perovskite films typically consist of multiple crystals with random orientations that include grain boundaries and various kinds of defects in their atomic crystal lattices. These often limit how well charge carriers (electrons or “holes”) can move through them.

Perovskites act as efficient catalysts for aldehyde alkylations

A research team led by San Diego State University chemists Xiaolin Zhu and Yong Yan has shown that perovskite materials methylammonium lead tribromide and the cesium analog are not only two of the most studied solar-cell perovskites, but can also function as highly active photocatalysts for organic synthesis.

Perovskites catalyze aldehyde alkylations image

The researchers used standard methods to prepare the low-cost nanocrystal catalysts and explored their reactivity under blue-light illumination in tests with 2-bromoacetophenone and octanal. The reactions generated a mixture of products, including the aldehyde α-alkylation product, other C-coupling products, and dehalogenated acetophenone.

Perovskites found promising as spintronics materials, researchers develop two new perovskite spintronics devices

Researchers from the University of Utah have developed two spintronics devices based on perovskite materials. The researchers used these new devices to demonstrate the high potential of perovksites for spintronics systems. This is a followup to the exciting results announced in 2017 by the same group that showed advantages of perovskites for spintronics.

Perovskite spintronics LED wavelength (Utah University)

The researchers used an organic-inorganic hybrid perovskite material with a heavy lead atom that features strong spin-orbit coupling and a long injected spin lifetime. The first device was a spintronic LED, which worked with a magnetic electrode instead of an electron-hole electrode. The perovskite LED lights up with circularly polarized electroluminescence.

UK researchers suggest a new way to improve the performance of perovskite solar cells

The performance pf perovskite-based solar cells is affected by several factors, one of which can be ion defects that can move around. As these defects move, they affect the internal electric environment within the cell. The Perovskite material is responsible for absorbing light to create electronic charge, and also for helping to extract the charge into an external circuit before it is lost to a process called 'recombination'. Most of the detrimental recombination can occur in different locations within the solar cell. In some designs it occurs mainly within the perovskite, while in others it happens at the edges of the perovskite where it contacts the adjacent materials known as transport layers.

Now, researchers from the Universities of Portsmouth, Southampton and Bath have developed a way to adjust the properties of the transport layers to encourage the ionic defects within the perovskite to move in such a way that they suppress recombination and lead to more efficient charge extraction - increasing the proportion of the light energy falling on the surface of the cell that can ultimately be used.

Chinese researchers create efficient perovskite-based solar cells using Graphdiyne, a unique carbon material

Researchers from the Chinese Academy of Sciences have reported that the introduction of a certain amount of graphdiyne (25%), a form of carbon material invented by Chinese scientists with independent intellectual property rights, as a host material in perovskite solar cells can successfully push the device efficiency up to 21.01%, achieving multiple positive effects of highly crystalline qualities, large domain sizes and few grain boundaries.

Chinese researchers create efficient perovskite-based solar cells using Graphdiyne, a unique carbon material image

The researchers also revealed that the current-voltage hysteresis was negligible, and device stability was improved as well. It was found that graphdiyne as the host active material significantly affects the crystallization, film morphology and a series of optoelectronic properties of perovskite active layer.

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 solar cell developer Swift Solar raises $4.6 million

Swift Solar logo imageSwift Solar, A U.S startup designing and manufacturing perovskite solar panels, has announced raising $4.6 million as part of a $6.6 million investment round.

The team at Swift Solar in Colorado includes leading solar technologists from Stanford, MIT, Cambridge (UK), Oxford (UK), and the University of Washington, with expertise in perovskite photovoltaic technology and scale-up. Swift’s core technologies range from new solar cell architectures to specialized manufacturing techniques initially developed in the labs at Stanford and MIT.