Transistors

Researchers from Northwestern University, University of Toronto, ShanghaiTech University, University of Victoria and Arizona State University have developed highly stable, highly efficient 0.05cm² perovskite solar cell with a PCE of 26.15%, certified by a National Renewable Energy Laboratory-accredited facility. The team said that the prior certified world record published in a scientific journal was 25.73%.

A 1.04 cm² device had a certified power conversion efficiency of 24.74%, also a record for its size. The best devices retained 95% of their initial PCE following 1,200 hours of continuous solar illumination at a temperature of 65 degrees.

Researchers at the University of Potsdam, Humboldt-University of Berlin, University of Wuppertal, Swansea University, University of Oxford, East China University of Science and Technology, Friedrich-Alexander-University Erlangen-Nürnberg and HZB have shown that ion-induced field screening is a dominant factor in the operational stability of perovskite solar cells (PSCS). 

The rather poor perovskite stability is usually attributed to electronic defects, electrode oxidation, the ionic nature of the perovskite, or chemical decomposition under moisture and oxygen. Understanding the underlying degradation mechanism is crucial to enable targeted improvements. "In our article, we demonstrate that an increasing concentration of defects in the cells is apparently not a decisive factor for degradation," says Martin Stolterfoht, former leader of the Heisenberg junior research group PotsdamPero at the University of Potsdam and now professor at the Chinese University of Hong Kong.

Researchers at the University of Oxford, University of Toronto, Peking University, Kunming Medical University, Yunnan University, Chinese Academy of Sciences (CAS) and Academia Sinica have reported a chemically stable and multifunctional buffer layer material, ytterbium oxide (YbOx), for p-i-n perovskite solar cells (PSCs) by scalable thermal evaporation deposition. 

This YbOx buffer has been used in p-i-n PSCs based on narrow-bandgap perovskite light-absorbing layers, with certified power conversion efficiencies exceeding 25%.

Researchers at Graphenea, University of Utah and Kairos Sensors have examined a perovskite-based graphene field effect transistor (P-GFET) device for X-ray detection.

The device architecture consisted of a commercially available GFET-S20 chip, produced by Graphenea, with a layer of methylammonium lead iodide (MAPbI₃) perovskite spin coated onto the top of it. This device was exposed to the field of a molybdenum target X-ray tube with beam settings between 20 and 60 kVp (X-ray tube voltage) and 30–300 μA (X-ray tube current). Dose measurements were taken with an ion-chamber and thermo-luminescent dosimeters and used to determine the sensitivity of the device as a function of the X-ray tube voltage and current, as well as source-drain voltage.

Researchers from Pohang University of Science and Technology (POSTECH), Chinese Academy of Sciences (CAS) and University of Electronic Science and Technology of China have developed perovskite transistors through the use of three distinct perovskite cation processes. 

The team showed that pure-tin perovskite thin-film transistors can be created using triple A cations of caesium–formamidinium–phenethylammonium. This approach reportedly leads to high-quality cascaded tin perovskite channel films with low-defect, phase-pure perovskite/dielectric interfaces.

TCI has launched a range of molecular dopants that can significantly increase the charge carrier density and modify the energy levels in organic electronics devices. Molecular dopants offer a versatile platform to tune the optoelectrical and electrical properties of organic semiconductors to application-specific demands, allowing advantages like increasing the electrical conductivity and mobility by orders of magnitude and improving contact properties in various electronic and optoelectronic devices.

TCI's p-type and n-type dopants can be applied to various organic electronics devices, such as: carrier transport layers of organic light-emitting diodes (OLEDs), organic photovoltaics (OPVs), perovskite solar cells (PSCs), and perovskite quantum dot LEDs, as well as active layers of organic field-effect transistors (OFETs), OPVs, and thermoelectric devices in the field of organic electronics research.

An international research group that included teams from Vrije Universiteit Amsterdam, University of Fribourg, the University of the Basque Country and the University of New South Wales has assessed the levels of efficiency and stability that perovskite solar cells (PSCs) have to achieve in order to become an economically viable technology to compete with crystalline silicon cells in the rooftop segment.

The scientists assessed the necessary lifetime (LT) of a perovskite module, which they defined as the time until a module has 80% of its initial efficiency, as a function of efficiencies to be competitive in the levelized cost of electricity (LCOE). They found that perovskite solar modules might need to provide 20% efficiency for at least 36 years, or 25% efficiency for a minimum of 21 years, if they want to compete with conventional PV panels.

Researchers at KIST and Gwangju Institute of Science and Technology (GIST), led by Dr. Yusin Pak at the Sensor System Research Center (KIST) and Professor Gun Young Jung at the School of Materials Science and Engineering (GIST), have developed ultra-high-speed, high-efficiency optoelectronic logic gates (OELGs) by using organic-inorganic perovskite photodiodes.

Demand is increasing for computers that can quickly calculate and process large amounts of information, as artificial intelligence, self-driving cars, drones, and metaverse technologies are drawing attention as core industries of the future. However, electronic semiconductor logic gates, which serve as the brains of computers, have limited capacity in high-speed data calculation and processing, and have disadvantages in that they consume a lot of energy and generate considerable heat.

A team of researchers from Pohang University of Science and Technology, University of Electronic Science and Technology of China and Sungkyunkwan University has improved the performance of a p-type semiconductor transistor, using inorganic metal halide perovskite.

One of the biggest advantages of the new technology is that it enables solution-processed perovskite transistors to be simply printed as semiconductor-like circuits.

Scientists at the National Renewable Energy Laboratory (NREL) have experimentally synthesized a nitride perovskite material that previously only existed in theory and measured its properties in collaboration with researchers at the Colorado School of Mines.

The new material could theoretically be used for microelectromechanical devices such as the ones used in telecommunications and other areas. Nitride perovskites have been computationally predicted to be stable, but not many have been synthesized, and their experimental properties remain largely unknown, the researchers explained in their new article.