Perovskite-based photovoltaic devices have garnered significant interest owing to their remarkable performance in converting light into electricity. Recently, the focus in the field of perovskite solar cells (PSCs) has shifted towards enhancing their durability over extended periods. One promising strategy is the incorporation of two-dimensional (2D) perovskites, known for their ability to enhance stability due to the large organic cations that act as a barrier against moisture. However, the broad optical bandgap and limited charge transport properties of 2D perovskites hinder their efficiency, making them less suitable as the sole light-absorbing material when compared to their three-dimensional (3D) counterparts. An innovative approach involves using 2D perovskite structures to modify the surface properties of 3D perovskite. This hybrid approach, known as 2D/3D perovskites, while enhancing their performance. Beyond solar energy applications, 2D perovskites offer a flexible platform for chemical engineering, allowing for significant adjustments to crystal and thin-film configurations, bandgaps, and charge transport properties through the different organic ligands and halide mixtures. Despite these advantages, challenges remain in integration of 2D perovskites into solar cells without compromising device stability. This review encapsulates the latest developments in 2D perovskite research, focusing on their structural, optoelectronic, and stability attributes, while delving into the challenges and future potential of these materials.

Artificial carbon fixation is a promising pathway for achieving the carbon cycle and environment remediation. However, the sluggish kinetics of oxygen evolution reaction (OER) and poor selectivity of CO₂ reduction seriously limited the overall conversion efficiencies of solar energy to chemical fuels. Herein, we demonstrated a facile and feasible strategy to rationally regulate the coordination environment and electronic structure of surface-active sites on both photoanode and cathode. More specifically, the defect engineering has been employed to reduce the coordination number of ultrathin FeNi catalysts decorated on BiVO₄ photoanodes, resulting in one of the highest OER activities of 6.51 mA cm⁻² (1.23 V_RHE, AM 1.5G). Additionally, single-atom cobalt (II) phthalocyanine anchoring on the N-rich carbon substrates to increase Co–N coordination number remarkably promotes CO₂ adsorption and activation for high selective CO production. Their integration achieved a record activity of 109.4 μmol cm⁻² h⁻¹ for CO production with a faradaic efficiency of > 90%, and an outstanding solar conversion efficiency of 5.41% has been achieved by further integrating a photovoltaic utilizing the sunlight (> 500 nm).

With climate change and higher incidence of crop diseases, global cocoa production and supply is being threatened. A research team from the National University of Singapore (NUS), motivated by these reports, set out to enhance the taste of carob, making it a more appealing and sustainable alternative to cocoa.

The NUS team, led by Associate Professor Liu Shao Quan from the Department of Food Science and Technology at the NUS Faculty of Science, has developed two innovative techniques to enhance the taste of carob pulp.

“Our carob-based innovation meets the relatively untapped and nascent market of alternative chocolate sources. Additionally, our new techniques improve the taste of carob itself, without the use of additives such as flavourings. So, consumers can have the best of both worlds – better flavour and a simple ingredients list. With these innovations, we aim to make a meaningful contribution towards addressing the current challenges and needs of the chocolate industry,” said Assoc Prof Liu.

A KAIST research team has drawn attention by developing a new water-based air purification technology that combines “nano water droplets that capture dust” with a “nano sponge structure that autonomously draws up water,” enabling dust removal using nano water droplets without filters, self-supplied water operation, and long-term, quiet, and safe performance.

Recently, addressing the inherent timescale mismatch challenge between fast and slow responses in optoelectronic sensors, a collaborative team from Suzhou Institute of Nano-Tech and Nano-Bionics (SINANO), Chinese Academy of Sciences (Yukun ZHAO, Shulong LU, Min JIANG), Fudan University (Lifeng BIAN), and Suzhou University of Science and Technology (Jianya ZHANG) has proposed an innovative monolithic integration scheme. By combining surface defect introduction and local contact interface design with a gallium nitride (GaN) nanowire lift-off technique that eliminates the interference from the underlying silicon substrate, the team integrates fast and slow responses into a single device. This results in a transparent bifunctional device capable of self-driven detection and neural synaptic integration, with omnidirectional (360°) detection capability. As a photodetector, the device demonstrates the millisecond-level response speeds, while it exhibits the second- to minute-level relaxation time as an artificial synapse, achieving an over 1000-fold contrast in response dynamics. The device has been validated in the intelligent perception systems for humanoid robots successfully, advancing the development of multifunctional monolithic optoelectronic devices and providing a solid foundation for further research in related fields.

 

The work entitled "A dual-mode transparent device for 360° quasi-omnidirectional self-driven photodetection and efficient ultralow-power neuromorphic computing" was published in Light: Science & Applications.

Metallenes are atomically thin metals, whose unique properties make them extremely promising for nanoscale applications. However, their extreme thinness makes them also flimsy. Now, researchers at the Nanoscience Center of the University of Jyväskylä (Finland) have succeeded in identifying the principles that can maximize their stability. The solution may open up opportunities in materials design, nano-electronics, energy production, and biomedicine.