EcoMat最新文献

Over the past decade, metal halide perovskites (MHPs) have received great attention, triggered by the tremendous success of their record-breaking power conversion efficiency values in solar cells. Recently, there have been significant interests in fully utilizing their unique properties by exploring other device applications including thermoelectrics, which is promising due to their ultralow thermal conductivity and high mobility relative to their competitors among solution-processable materials. However, the performance of MHP thermoelectrics reported so far falls significantly short of theoretical predictions, as the doping levels achieved to date are typically below the optimum values for maximizing the thermoelectric power factor, indicating the need for effective electrical doping strategies. In this critical review, recent studies aimed at enhancing the thermoelectric properties of MHPs are discussed, with a focus on the relatively under-explored area of electrical doping in MHPs. The underlying charge transport mechanism and doping effect on transport are also examined. Finally, the challenges facing MHP thermoelectrics are highlighted, and potential research visions for achieving highly efficient thermoelectric conversion based on MHPs are offered.

All-inorganic perovskite solar cells have shown great potential owing to their superior stability against thermal stress and moisture compared to organic–inorganic perovskite solar cells. However, there are some remaining issues in the all-inorganic perovskite solar cell fabrication process, such as the low solubility of the perovskite precursors and the occurrence of the secondary phases. In this review, we focus on all-inorganic CsPbBr₃ perovskite solar cells and categorize them based on their fabrication process. Various processes and strategies that have been developed to solve the aforementioned issues including the general process of multistep spin coating are thoroughly investigated. Finally, a summary of the various processes for the all-inorganic CsPbBr₃ perovskite solar cells and an outlook for the development of highly efficient all-inorganic perovskite solar cells are proposed.

Although perovskite solar cells have achieved efficiency over 25%, the toxic of Pb content remains severe problem given its commercial prospect. Especially when the devices suffer harsh weather, the Pb content can easily leak out to soil and water. Chelating resins (CRs) exhibit excellent superiority in treating waste water in industrial field, since the functional groups in CRs can adsorb divalent metal ion to soften and purify waste water. Herein, an iminodiacetic acid (IDA)-CR is introduced as encapsulation over perovskite solar cells for the first time. The IDA-CR exhibits high surface area and excellent adsorption capability. Qualitative and quantitative analysis of Pb leakage are studied, and the devices with encapsulation of IDA-CR can detain over 90% of Pb compared with control devices without encapsulation after immersed in deionized water for 12 h even in acid situation or after heating. This IDA-CR method provides a new strategy towards environmental and biological-friendly perovskite optoelectronic devices.

Typically n-i-p structured perovskite solar cells (PSCs) incorporate 2,2′,7,7′-tetrakis (N,N-di-p-methoxyphenyl amine)-9,9′-spirobifluorene (spiro-OMeTAD) as the hole-transporting material. Chemical doping of spiro-OMeTAD involves a lithium bis(trifluoromethyl sulfonyl)imide dopant, causing complex side-reactions that affect the device performance, which are not fully understood. Here, we investigate the aging-dependent device performance of widely used formamidinium lead triiodide (FAPbI₃)-based PSCs correlated with lithium-ion (Li⁺) migration. Comprehensive analyses reveal that Li⁺ ions migrate from spiro-OMeTAD to perovskite, SnO₂, and their interfaces to induce the phase-back conversion of α-FAPbI₃ to δ-FAPbI₃, generation and migration of iodine defects, and de-doping of spiro-OMeTAD. The rapid performance drop of FAPbI₃-based PSCs, even aging under dark conditions, is attributed to a series of these processes. This study identifies the hidden side effects of Li⁺ ion migration in FAPbI₃-based PSCs that can guide further work to maximize the operational stability of PSCs.

Perovskite-based tandem cells are emerging as new photovoltaic (PV) cells with a high efficiency that exceeds the efficiency limit of single-junction cells. Building-integrated PVs that require high efficiency are attractive, but aesthetics play key roles in these urban applications. One of the most challenging problems with respect to aesthetic PV cells is the efficiency loss due to color tuning. Here, we demonstrate for the first time lossless full-color tunable PV cells based on the use of textured luminescent down-shifting (LDS) films with LDS dyes with ultraviolet-selective absorption. The LDS anti-reflection (AR) films improve the perovskite/Si tandem cell efficiency by reducing the loss of parasitic UV absorption of the layers above the perovskite film due to LDS effect and the loss due to cell reflection due to the textured surface. Therefore, color tuning with LDS AR films can be used to produce highly aesthetic and efficient PV cells for urban applications.

Global warming has been affecting human health, including direct mortality and morbidity from extreme heat, storms, drought, and indirect infectious diseases. It is not only “global” but extremely “personal”—it is a matter of life and death for many of us. In this perspective, we propose the use of wearable technologies for localized personal thermoregulation as an innovative method to reduce the impact on health and enable wider adaptability to extreme thermal environments. The state-of-the-art thermoregulation methods and wearable sensing technologies are summarized. In addition, the feasibility of thermoregulation technology in preventive medicine for promoting health under climate change is comprehensively discussed. Further, we provide an outlook on health-oriented closed loop that can be achieved based on parallel thermoregulation and multiple data inputs from the physiological, environmental, and psychological cues, which could promote individuals and the public to better adapt to global warming.

Rechargeable zinc-air batteries (ZABs) are cost-effective energy storage devices and display high-energy density. To realize high round-trip energy efficiency, it is critical to develop durable bi-functional air electrodes, presenting high catalytic activity towards oxygen evolution/reduction reactions together. Herein, we report a nanocomposite based on ternary CoNiFe-layered double hydroxides (LDH) and cobalt coordinated and N-doped porous carbon (Co-N-C) network, obtained by the in-situ growth of LDH over the surface of ZIF-67-derived 3D porous network. Co-N-C network contributes to the oxygen reduction reaction activity, while CoNiFe-LDH imparts to the oxygen evolution reaction activity. The rich active sites and enhanced electronic and mass transport properties stemmed from their unique architecture, culminated into outstanding bi-functional catalytic activity towards oxygen evolution/reduction in alkaline media. In ZABs, it displays a high peak power density of 228 mW cm⁻² and a low voltage gap of 0.77 V over an ultra-long lifespan of 950 h.

Surface chemistry of MXenes is of significant interest due to its potential to control their final optoelectronic and physicochemical properties, and address the oxidation and dispersion stabilities of MXenes. Surface chemistry of MXenes can be manipulated by either MXene synthesis via chemical etching or post surface functionalization method. Although numerous reviews have explored MXene synthesis methods, there has been a lack of focus on post surface functionalization. This review aims to fill this gap by summarizing recent advancements in the MXene surface functionalization chemistry, and elucidating mechanisms, properties, and future perspectives of functionalized MXenes. We discuss organic ligand molecules, such as organic salts, catechols, phosphonates, carboxylates, and silanes, which can be employed to surface-functionalize MXene through covalent or non-covalent bond interaction. This comprehensive review offers valuable insights for scientists and engineers in utilizing functionalized MXenes across diverse applications, including EMI shielding, energy storage, electronics, optoelectronics, and sensors.