Technical / research - Page 59

Scientists from École Polytechnique Fedérale de Lausanne (EPFL), University of Luxembourg, Empa-Swiss Federal Laboratories for Materials Science and Technology and CNRS have demonstrated a simple approach to designing the interface between two layers in a perovskite solar cell, improving both the performance and stability of the device.

Solar cells fabricated by the group achieved 23.4% conversion efficiency, and were operated for close to 6,000 hours before degrading beyond 80% of this initial value.

Researchers from Russia-based ITMO University and the University of Rome Tor Vergata have developed a paste made of titanium dioxide (TiO₂) and resonant silicon nanoparticles, claimed to improve light absorption in perovskite solar cells based on methylammonium lead iodide (MAPbI₃).

The scientists created a mesoporous electron transport layer based on optically resonant silicon nanoparticles which were then incorporated into TiO₂ paste. 'Such particles serve as nanoantennae ' they catch light and it resonates inside them. And the longer light stays in the photoactive layer, the more of it is absorbed by the material,' said Sergey Makarov, professor at ITMO's school of physics and engineering.

ITMO scientists have created perovskite nanocrystals that preserve their unique optical properties in water and biological fluids. This material could offer new opportunities for the optical visualization of biological objects and promote the investigation of internal organs in living organisms and monitoring of diseases.

Nanomaterials based on halide perovskites hold great potential for use in bioimaging: perovskite nanoparticles can be potentially applied for visualization purposes in order to study biological processes in cells and living organisms. However, the main limitation that prevents their application as luminescent markers is their instability in aqueous solutions.

Researchers from Japan's Tsukuba University have found that ultraviolet light can modulate oxide ion transport in a perovskite crystal at room temperature.

The performance of battery and fuel cell electrolytes depends on the motions of electrons and ions within the electrolyte. Modulating the motion of oxide ions within the electrolyte could enhance future battery and fuel cell functionality by increasing the efficiency of the energy storage and output. Use of light to modulate the motions of ions - which expands the source of possible energy inputs - has only been demonstrated thus far for small ions such as protons. Overcoming this limitation of attainable ion motions is something the researchers in this study aimed to address.

Researchers from Italy's CNR-IMM, Università del Salento, Università degli Studi di Catania and University of Bari 'Aldo Moro' have developed an innovative vacuum deposition method to prepare thin CH₃NH₃PbI₃ (MAPbI₃) layers for semitransparent perovskite solar cells.

Schematic of three physical deposition methods. Image from article

This new (patent pending) method to deposit thin perovskite layers for PSC under low vacuum conditions is called LV-PSE (low vacuum proximity space effusion) and can reportedly reduce costs and waste.

Skoltech researchers, along with colleagues from the RAS Institute for Problems of Chemical Physics, have synthesized a new conjugated polymer for organic electronics using two different chemical reactions and shown the impact of the two methods on its performance in organic and perovskite solar cells.

Perovskite solar cells have reached impressive certified record efficiencies, but long-term stability remains an issue. Recent research has shown that device stability can be improved by covering the photoactive perovskite material with a charge-extraction layer that provides efficient encapsulation. Among other materials, this protective function may be fulfilled by conjugated polymers.

Scientists from the Soochow University (Suzhou), the Chinese Academy of Sciences, East China Normal University (Shanghai) and Ural Federal University have developed an architecture of red-emitting perovskite LEDs (PeLEDs) that minimizes optical energy loss and significantly increases their efficiency and longevity.

The new work may open the door to high-performance LEDs for lighting devices, displays and other electronic devices. These could be energy efficient and at the same time have high brightness and long operating time.

A team of researchers, led by Professor Yabing Qi in the Energy Materials and Surface Sciences Unit at the Okinawa Institute of Science and Technology Graduate University (OIST) in Japan, recently imaged the atoms at the surface of the light-absorbing layer metal-halide perovskite solar cell.

Their findings addressed a long-standing mystery in the field of solar power technology, showing how power-boosting and stability-enhancing chlorine is incorporated into the perovskite material.

Researchers from ITMO's School of Physics and Engineering have created a paste, made of titanium dioxide and resonant silicon nanoparticles, meant to increase the generation of photocurrent in perovskite solar cells and maximize their efficiency.

Image by ITMO

One of two strategies is usually used to further boost the efficiency of PSCs: improving the charge collection or increasing light absorption by the charge generating layer. The first strategy also means the need to introduce other substances or 2D structures into perovskites, which makes the resulting devices more expensive. The ITMO team, together with colleagues from Tor Vergata University, went around this problem by using Mie-resonant silicon nanoparticles, as silicon is one of the elements most accessible in nature.

A research group, led by Prof. Han Keli from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS), in collaboration with Prof. Miao Xiangyang's group from Shanxi Normal University, recently explored the colloidal synthesis of all-inorganic rare-earth-based double perovskite NCs with NIR emission, and revealed their exciton dynamics.

Previous studies mainly focused on the photoluminescence (PL) in the visible region, and those on the near-infrared (NIR) PL of lead-free perovskite NCs are rare.