Highly efficient esterification of waxy maize starch in choline chloride/acetic acid acidic deep eutectic solvent system.

In this study, to address the issue of solvent selection in the chemical modification of starch, a method was developed for the efficient esterification of waxy maize starch (WMS) using an acidic deep eutectic solvent composed of choline chloride and acetic acid (CCHAc-ADES). The impact of different mass fractions of CCHAc-ADES on the degree of substitution and reaction efficiency of lauric acid starch esters was explored. It was found that under the conditions of 70 wt% CCHAc-ADES, starch esters with the highest degree of substitution of 0.

Sn-Pb Perovskite with Strong Light and Oxygen Stability for All-Perovskite Tandem Solar Cells.

Research on mixed Sn-Pb perovskite solar cells (PSCs) is gaining significant attention due to their potential for high efficiency in all-perovskite tandem solar cells. However, Sn in Sn-Pb perovskite is susceptible to oxidation, leading to a high defect density. The oxidation primarily occurs through two pathways: one involving a reaction with oxygen, and the other related to iodine defects, which generate I and further accelerate the oxidation of Sn⁺, greatly reducing stability.

Universal Approach for Managing Iodine Migration in Inverted Single-Junction and Tandem Perovskite Solar Cells.

Despite significant progress in the power-conversion efficiency (PCE) of perovskite solar cells (PSCs), the instability of devices remains a considerable obstacle for commercial applications. This instability primarily originates from the migration of halide ions-particularly iodide ions (I). Under light exposure and thermal stress, I migrates and transforms into I, leading to irreversible degradation and performance loss.

Fluorinated Naphthalene Diimides as Buried Electron Transport Materials Achieve Over 23% Efficient Perovskite Solar Cells.

Naphthalene diimides (NDI) are widely serving as the skeleton to construct electron transport materials (ETMs) for optoelectronic devices. However, most of the reported NDI-based ETMs suffer from poor interfaces with the perovskite which deteriorates the carrier extraction and device stability. Here, a representative design concept for editing the peripheral groups of NDI molecules to achieve multifunctional properties is introduced.

Structurally Flexible 2D Spacer for Suppressing the Electron-Phonon Coupling Induced Non-Radiative Decay in Perovskite Solar Cells.

This study presents experimental evidence of the dependence of non-radiative recombination processes on the electron-phonon coupling of perovskite in perovskite solar cells (PSCs). Via A-site cation engineering, a weaker electron-phonon coupling in perovskite has been achieved by introducing the structurally soft cyclohexane methylamine (CMA) cation, which could serve as a damper to alleviate the mechanical stress caused by lattice oscillations, compared to the rigid phenethyl methylamine (PEA) analog. It demonstrates a significantly lower non-radiative recombination rate, even though the two types of bulky cations have similar chemical passivation effects on perovskite, which might be explained by the suppressed carrier capture process and improved lattice geometry relaxation.

Dynamic Reversible Oxidation-Reduction of Iodide Ions for Operationally Stable Perovskite Solar Cells under ISOS-L-3 Protocol.

Despite rapid advancements in the photovoltaic efficiencies of perovskite solar cells (PSCs), their operational stability remains a significant challenge for commercialization. This instability mainly arises from light-induced halide ion migration and subsequent oxidation into iodine (I). The situation is exacerbated when considering the heat effects at elevated temperatures, leading to the volatilization of I and resulting in irreversible device degradation.

The Influence of Donor/Acceptor Interfaces on Organic Solar Cells Efficiency and Stability Revealed through Theoretical Calculations and Morphology Characterizations.

End-groups halogenation strategies, generally refers to fluorination and chlorination, have been confirmed as simple and efficient methods to regulate the photoelectric performance of non-fullerene acceptors (NFAs), but a controversy over which one is better has existed for a long time. Here, two novel NFAs, C9N3-4F and C9N3-4Cl, featured with different end-groups were successfully synthesized and blended with two renowned donors, D18 and PM6, featured with different electron-withdrawing units. Detailed theoretical calculations and morphology characterizations of the interface structures indicate NFAs based on different end-groups possess different binding energy and miscibility with donors, which shows an obvious influence on phase-separation morphology, charge transport behavior and device performance.

Nucleation Regulation and Mesoscopic Dielectric Screening in α-FAPbI.

While significant advancements in power conversion efficiencies (PCEs) of α-FAPbIperovskite solar cells (PSCs) have been made, attaining controllable perovskite crystallization is still a considerable hurdle. This challenge stems from the initial formation of δ-FAPbI, a more energetically stable phase than the desired black α-phase, during film deposition. This disrupts the heterogeneous nucleation of α-FAPbI, causing the formation of mixed phases and defects.

Epitaxial Growth of α-FAPbI at a Well-Matched Heterointerface for Efficient Perovskite Solar Cells and Solar Modules.

Although the FAPbI perovskite system exhibits an impressive optoelectronic characteristic and thermal stability because of its energetically unstable black phase at room temperature, it is considerably challenging to attain a controllable and oriented nucleation of α-FAPbI . To overcome this challenge, a 2D perovskite with a released inorganic octahedral distortion designed by weakening the hydrogen interactions between the organic interlayer and [PbI ] octahedron is presented in this study. A highly matched heterointerface can be formed between the (002) facet of the 2D structure and the (100) crystal plane of the cubic α-FAPbI , thereby lowering the crystallization energy and inducing a heterogeneous nucleation of α-FAPbI .

Two-photon 3D printing diaphragm-integrated ring waveguide coupler for ultrasound detection.

We demonstrate a diaphragm-integrated ring waveguide coupler fabricated by the two-photon direct laser wring technique as an ultrasonic sensor, which is integrated on an optical fiber tip. The device consists of a micro-ring waveguide with a diameter of 5 µm functionalized as an optical fiber tip light reflection mirror and a straight waveguide connecting a diaphragm. The evanescent field coupling can be realized between the two waveguides, and the coupling efficiency can be changed due to the variation of the coupling gap induced by ultrasound.

Rational Design of Ferroelectric 2D Perovskite for Improving the Efficiency of Flexible Perovskite Solar Cells Over 23 .

Despite the great progress of flexible perovskite solar cells (f-PSCs), it still faces several challenges during the homogeneous fabrication of high-quality perovskite thin films, and overcoming the insufficient exciton dissociation. To the ends, we rationally design the ferroelectric two-dimensional (2D) perovskite based on pyridine heterocyclic ring as the organic interlayer. We uncover that incorporation of the ferroelectric 2D material into 3D perovskite induces an increased built-in electric field (BEF), which enhances the exciton dissociation efficiency in the device.