Researchers from TNO at Holst Centre, Solliance and TU/e have jointly developed a thin and flexible perovskite-based scanner for fingerprints.

Low-resolution image-sensor arrays have been demonstrated in the past, but the high-resolution, high pixel-count image sensors suitable for commercial applications have not yet been truly achieved. The thin and flexible scanner in this new work is based on metal-halide perovskites (MHPs). Gerwin Gelinck, Chief Technology Officer TNO at Holst Centre, elaborates on the new study: 'Perovskites are marvelous materials! For the first time we show that these materials are also very good for light imaging and sensing applications. When combined with display-like transistors, we made a scanner that can capture high-resolution color images as well as biometric fingerprinting'.

A team of researchers from Oak Ridge National Laboratory, Florida State University, Argonne National Laboratory, University of Pittsburgh, Pittsburgh Quantum Institute and Sungkyunkwan University has found a rare quantum material in which electrons move in coordinated ways, essentially 'dancing.'

Straining the material creates an electronic band structure that sets the stage for exotic, more tightly correlated behavior ' similar to tangoing ' among Dirac electrons, which are especially mobile electric charge carriers that may someday enable faster transistors.

Researchers from the UK's University of Bath and Germany's Max Planck Institute for Polymer Research have developed a way to make perovskite-based components for low-cost electronics.

The physicists have found a way to make perovskite-based transistors, while overcoming the problem of the material's ion content interfering with the flow of electronic current through a transistor. This breakthrough may pave the way for research into greener electronic components for low-cost electronic devices.

Organic-inorganic hybrid perovskites (OIHPs) have great potential for various applications like solar cells, lighting-emitting diodes (LEDs), field effect transistors (FETs) and photodetectors. Among their most important parameters influencing the power conversion efficiency (PCE) of devices based on perovskite materials is their carrier mobility. However, despite massive progress made by introducing new components into the structure to control the mobility of the carriers, the understanding on the atom level of how the components affect the performance is still lacking.

To address this problem, a research team led by Prof. Luo Yi and Prof. Ye Shuji from the University of Science and Technology of China (USTC) of the Chinese Academy of Sciences (CAS) has synthesized a series of 2D OHIPs films with large organic spacer cations.

Researchers from Pohang University of Science and Technology in Korea have received Universal Display Corporation's 2020 Innovative Research and Pioneering Technology Award in Organic Electronics & Display, for their work 'High-Performance and Reliable Lead-Free Layered-Perovskite Transistors'. Universal Display (UDC) is a large OLED research company, considered to be a pioneer in field.

In their work, the scientists explain that despite extensive examination of perovskites' potential use in solar cells and light'emitting diodes, research on their applications in thin'film transistors (TFTs) has drawn less attention despite their high intrinsic charge carrier mobility. In this study, the universal approaches for high'performance and reliable p'channel lead'free phenethylammonium tin iodide TFTs are reported.

A Purdue University-led research team discovered that adding a rigid bulky molecule ' bithiophenylethylammonium ' to the surface of a perovskite stabilizes the movement of ions, preventing chemical bonds from breaking easily. The researchers also demonstrated that adding this molecule makes a perovskite stable enough to form clean atomic junctions with other perovskites, allowing them to stack and integrate.

'If an engineer wanted to combine the best parts about perovskite A with the best parts about perovskite B, that typically can't happen because the perovskites would just mix together,' said Brett Savoie, a Purdue assistant professor of chemical engineering. 'In this case, you really can get the best of A and B in a single material. That is completely unheard of.'

University of California, Berkeley, scientists have created a blue light-emitting diode (LED) from halide perovskites, overcoming a major barrier to using these cheap, easy-to-make materials in electronic devices.

In the process, however, the researchers discovered a fundamental property of halide perovskites that may prove a barrier to their widespread use as solar cells and transistors. Alternatively, this unique property may open up a whole new world for perovskites far beyond that of today's standard semiconductors.

Scientists at Duke University have used their electronic structure based materials modeling software on a supercomputer to help demonstrate the advantages of incorporating organic building blocks into hybrid perovskites.

The models showed that the new materials feature improved stability and safety while exhibiting a 'quantum well' behavior that can improve the performance of optoelectronic devices such as solar cells, LEDs and optical computers, making the hybrid perovskites more attractive for use in a broad range of applications.

Researchers at KU Leuven have explained how a promising type of perovskites can be stabilized. The team has developed a process in which the crystals turn black, enabling them to absorb sunlight. This is said to be necessary in order to use them in solar panels.

"Silicon forms a very strong, rigid crystal. If you press on it, it won't change its shape. On the other hand, perovskites are much softer and more malleable," explains Dr. Julian Steele of the KU Leuven Centre for Membrane Separations, Adsorption, Catalysis, and Spectroscopy for Sustainable Solutions (cMACS). "We can stabilize them under various lab conditions, but at room temperature, the black perovskite atoms really want to reshuffle, change structure, and ultimately turn the crystal yellow".

Researchers from Rutgers University, University of Minnesota and University of Texas at Dallas in the U.S have discovered a new type of electric field effect that can control light emission from perovskite devices.

The electric field effect usually refers to the modulation of electrical conductivity in a semiconductor by means of an applied voltage to a gate electrode and forms the basis of modern digital electronics. In a conventional field effect transistor (FET), the conductivity of a semiconductor layer can be turned on or off or gradually ramped up or down. Now, the research team has found that the photoluminescence (PL) of a perovskite device can be modulated in a similar manner. 'Our work reports a novel type of field effect in which PL, rather than conductivity, is tuned by an 'electric knob' ' the gate voltage,' explains Vitaly Podzorov, who led the research.