《自然》（20240411出版）一周論文導讀

Nature, 11 April 2024, VOL 628, ISSUE 8007

《自然》2024年4月11日，第628卷，8007期

材料科學Materials Science

Dopant-additive synergism enhances perovskite solar modules

摻雜劑—添加劑協同增強鈣鈦礦太陽能組件

▲ 作者：Bin Ding, Yong Ding, Jun Peng, Jan Romano-deGea, Lindsey E. K. Frederiksen, Hiroyuki Kanda, et al.

▲ 鏈接：

https://www.nature.com/articles/s41586-024-07228-z

▲ 摘要：

鈣鈦礦太陽能電池（PSCs）因其獨特的光電特性而成為最有前景的光伏技術之一。然而，與實驗室規模的PSCs相比，大面積PSCs的效率較低、穩定性差和可重復性低等問題是阻礙其商業化的主要瓶頸。

研究組報道了一種使用氯化甲銨（MACl）為摻雜劑、1,3—雙（氰基甲基）氯化咪唑鎓（[Bcmim]Cl）為路易斯堿離子液體添加劑的協同摻雜劑—添加劑組合策略。該策略有效地抑制了鈣鈦礦前驅體溶液（PPS）的降解，抑制了MACl的聚集，得到了相均勻、穩定、結晶度高、缺陷較少的鈣鈦礦薄膜。

該方法助力鈣鈦礦太陽能組件（PSM）的制造，在27.22 cm²的孔徑面積上認證效率達到23.30%，最終穩定在22.97%，標志著最高的認證PSM性能。此外，PSM表現出長期的運行穩定性，在室溫下一倍太陽光照連續1000小時后仍保持94.66%的初始效率。

研究組廣泛分析了[Bcmim]Cl和MACl之間的相互作用，以揭示導致器件性能增強的機制。該方法有望彌合從實驗臺到屋頂的差距，推進大面積鈣鈦礦光伏的生產和商業化。

▲ Abstract：

Perovskite solar cells (PSCs) are among the most promising photovoltaic technologies owing to their exceptional optoelectronic properties. However, the lower efficiency, poor stability and reproducibility issues of large-area PSCs compared with laboratory-scale PSCs are notable drawbacks that hinder their commercialization. Here we report a synergistic dopant-additive combination strategy using methylammonium chloride (MACl) as the dopant and a Lewis-basic ionic-liquid additive, 1,3-bis(cyanomethyl)imidazolium chloride ([Bcmim]Cl). This strategy effectively inhibits the degradation of the perovskite precursor solution (PPS), suppresses the aggregation of MACl and results in phase-homogeneous and stable perovskite films with high crystallinity and fewer defects. This approach enabled the fabrication of perovskite solar modules (PSMs) that achieved a certified efficiency of 23.30% and ultimately stabilized at 22.97% over a 27.22-cm2 aperture area, marking the highest certified PSM performance. Furthermore, the PSMs showed long-term operational stability, maintaining 94.66% of the initial efficiency after 1,000 h under continuous one-sun illumination at room temperature. The interaction between [Bcmim]Cl and MACl was extensively studied to unravel the mechanism leading to an enhancement of device properties. Our approach holds substantial promise for bridging the benchtop-to-rooftop gap and advancing the production and commercialization of large-area perovskite photovoltaics.

Triple-junction solar cells with cyanate in ultrawide-bandgap perovskites

超寬帶隙鈣鈦礦中氰酸鹽三結太陽能電池

▲ 作者：Shunchang Liu, Yue Lu, Cao Yu, Jia Li, Ran Luo, Renjun Guo, et al.

▲ 鏈接：

https://www.nature.com/articles/s41586-024-07226-1

▲ 摘要：

沒有質量損失的鈣鈦礦帶隙調諧使鈣鈦礦在太陽能吸收劑中獨樹一幟，為串聯太陽能電池提供了頗有前景的途徑。然而對于三結串聯應用而言，當鈣鈦礦帶隙增加到1.90 eV以上時，最小化電壓損失頗具挑戰性。

研究組提出了一種此前未知的假鹵化物，即氰酸鹽（OCN^?），其有效離子半徑（1.97 ?）與溴化物（1.95 ?）相當，可作為溴化物的替代品。電子顯微鏡和X射線散射證實了OCN摻入至鈣鈦礦晶格中。

這促成了顯著的晶格畸變，范圍從90.5°到96.6°，碘化物—溴化物分布均勻，微應變一致。由于這些效應，OCN基鈣鈦礦表現出增強的缺陷形成能和顯著降低的非輻射復合。

研究組實現了一個倒置鈣鈦礦（1.93 eV）單結器件，開路電壓（VOC）為1.422 V，VOC×FF（填充因子）乘積超過了Shockley-Queisser極限的80%，且在最大功率點跟蹤下性能穩定，最終獲得了1 cm²孔徑面積下效率為27.62%（認證效率為27.10%）的鈣鈦礦—鈣鈦礦—硅三結太陽能電池。

▲ Abstract：

Perovskite bandgap tuning without quality loss makes perovskites unique among solar absorbers, offering promising avenues for tandem solar cells. However, minimizing the voltage loss when their bandgap is increased to above 1.90 eV for triple-junction tandem use is challenging. Here we present a previously unknown pseudohalide, cyanate (OCN^?), with a comparable effective ionic radius (1.97?) to bromide (1.95?) as a bromide substitute. Electron microscopy and X-ray scattering confirm OCN incorporation into the perovskite lattice. This contributes to notable lattice distortion, ranging from 90.5° to 96.6°, a uniform iodide–bromide distribution and consistent microstrain. Owing to these effects, OCN-based perovskite exhibits enhanced defect formation energy and substantially decreased non-radiative recombination. We achieved an inverted perovskite (1.93 eV) single-junction device with an open-circuit voltage (VOC) of 1.422 V, a VOC× FF (fill factor) product exceeding 80% of the Shockley–Queisser limit and stable performance under maximum power point tracking, culminating in a 27.62% efficiency (27.10% certified efficiency) perovskite–perovskite–silicon triple-junction solar cell with 1 cm² aperture area.

Metal telluride nanosheets by scalable solid lithiation and exfoliation

金屬碲化物納米片的可擴展固相鋰化和剝離

▲ 作者：Liangzhu Zhang, Zixuan Yang, Shun Feng, Zhuobin Guo, Qingchao Jia, Huidan Zeng, et al.

▲ 鏈接：

https://www.nature.com/articles/s41586-024-07209-2

▲ 摘要：

過渡金屬碲化物（TMTs）是探索凝聚態物理、化學和材料科學中奇異性質的理想材料。雖然TMT納米片已通過自上而下的剝離成功制備，但其規模低于克級，并且需要較長的加工時間，限制了其從實驗室到市場的有效應用。

研究組報道了快速和可擴展地合成各種MTe₂（M = Nb、Mo、W、Ta、Ti）納米片的方法，即在10分鐘內將塊體MTe₂固相鋰化，并在幾秒鐘內將其水解。以NbTe₂為代表，他們生產了超過100克（108克）的NbTe₂納米片，平均厚度為3.2 nm，平均橫向尺寸為6.2 μm，且收率高（>80%）。

還觀察到一些有趣的量子現象（如量子振蕩和巨磁阻效應），這通常僅限于高度結晶的MTe₂納米片。TMT納米片還可作為鋰氧電池的電催化劑和微型超級電容器（MSCs）的電極。此外，該合成方法對制備合金碲化物、硒化物和硫化物納米片也有效。

該工作為TMT納米片的通用和可擴展合成開辟了新機遇，以探索新的量子現象、潛在應用和商業化。

▲ Abstract：

Transition metal tellurides (TMTs) have been ideal materials for exploring exotic properties in condensed-matter physics, chemistry and materials science. Although TMT nanosheets have been produced by top-down exfoliation, their scale is below the gram level and requires a long processing time, restricting their effective application from laboratory to market. We report the fast and scalable synthesis of a wide variety of MTe₂ (M = Nb, Mo, W, Ta, Ti) nanosheets by the solid lithiation of bulk MTe₂ within 10 min and their subsequent hydrolysis within seconds. Using NbTe₂ as a representative, we produced more than a hundred grams (108 g) of NbTe₂ nanosheets with 3.2 nm mean thickness, 6.2 μm mean lateral size and a high yield (>80%). Several interesting quantum phenomena, such as quantum oscillations and giant magnetoresistance, were observed that are generally restricted to highly crystalline MTe₂ nanosheets. The TMT nanosheets also perform well as electrocatalysts for lithium–oxygen batteries and electrodes for microsupercapacitors (MSCs). Moreover, this synthesis method is efficient for preparing alloyed telluride, selenide and sulfide nanosheets. Our work opens new opportunities for the universal and scalable synthesis of TMT nanosheets for exploring new quantum phenomena, potential applications and commercialization.

化學Chemistry

Force-controlled release of small molecules with a rotaxane actuator

利用輪烷致動器實現小分子的力控釋放

▲ 作者：Lei Chen, Robert Nixon & Guillaume De Bo

▲ 鏈接：

https://www.nature.com/articles/s41586-024-07154-0

▲ 摘要：

在醫療或材料領域，小分子的力控釋放為藥物遞送和治療劑或報告劑的釋放提供了巨大前景。在聚合物機械化學中，聚合物被用作拉伸機械敏感分子（機械基團）的致動器。這種技術可通過重排（機械載體中鍵斷裂的直接或間接結果），或通過籠狀、超分子或金屬配合物的解離，甚至通過“柔性激活”來釋放分子貨物。

然而，迄今為止所描述的系統在每次拉伸事件中釋放分子的多樣性和/或數量方面都頗受限。這是由于難以迭代激活剪式機械載體，因為致動聚合物在第一次激活后會解離。物理封裝策略可用于遞送更大的貨物負載，但這些通常受到非特定（即非機械）釋放的影響。

研究組展示了輪烷（一種互鎖分子，其中一個大環被捕獲在帶塞的軸上）作為一種有效致動器來觸發附加在其軸上的貨物分子的釋放。在溶液中通過超聲處理以及在固塊中通過壓縮處理，每個輪烷致動器可釋放多達5個貨物分子，釋放效率分別高達71%和30%，這使該輪烷裝置成為迄今為止實現的最有效釋放系統之一。

研究組還演示了三種代表性功能分子（藥物、熒光標簽和有機催化劑）的釋放，并預計該設備可釋放多種貨物分子。該輪烷致動器為各種力控釋放應用提供了一個通用平臺。

▲ Abstract：

Force-controlled release of small molecules offers great promise for the delivery of drugs and the release of healing or reporting agents in a medical or materials context. In polymer mechanochemistry, polymers are used as actuators to stretch mechanosensitive molecules (mechanophores). This technique has enabled the release of molecular cargo by rearrangement, as a direct or indirect consequence of bond scission in a mechanophore, or by dissociation of cage, supramolecular or metal complexes, and even by ‘flex activation’. However, the systems described so far are limited in the diversity and/or quantity of the molecules released per stretching event. This is due to the difficulty in iteratively activating scissile mechanophores, as the actuating polymers will dissociate after the first activation. Physical encapsulation strategies can be used to deliver a larger cargo load, but these are often subject to non-specific (that is, non-mechanical) release. Here we show that a rotaxane (an interlocked molecule in which a macrocycle is trapped on a stoppered axle) acts as an efficient actuator to trigger the release of cargo molecules appended to its axle. The release of up to five cargo molecules per rotaxane actuator was demonstrated in solution, by ultrasonication, and in bulk, by compression, achieving a release efficiency of up to 71% and 30%, respectively, which places this rotaxane device among the most efficient release systems achieved so far. We also demonstrate the release of three representative functional molecules (a drug, a fluorescent tag and an organocatalyst), and we anticipate that a large variety of cargo molecules could be released with this device. This rotaxane actuator provides a versatile platform for various force-controlled release applications.

Couple-close construction of polycyclic rings from diradicals

雙自由基偶聯-環化策略構建多環化物

▲ 作者：Alice Long, Christian J. Oswood, Christopher B. Kelly, Marian C. Bryan & David W. C. MacMillan

▲ 鏈接：

https://www.nature.com/articles/s41586-024-07181-x

▲ 摘要：

雜芳烴是生物活性分子中普遍存在的結構骨架，與其芳烴對應物相比，具有良好的物理性質。特別是，半飽和雜芳烴具有吸引人的溶解性和較高的sp3碳分數，可提高結合親和力和特異性。

然而，由于目前合成方法的限制，這些理想結構仍很少見。事實上，半飽和雜環化合物大多通過非模塊化的符合預期合成方法艱難制備而成，這降低了產率，限制了化學多樣性，在先導物競爭中不占優勢。

研究組描述了一種更直觀和模塊化的偶聯—環化方法來構建由雙自由基前驅體組成的半飽和環體系。該平臺將金屬光氧化還原C(sp²) —C (sp³)交叉偶聯與分子內Minisci型自由基環化相結合，將豐富的雜芳基鹵化物與簡單的雙官能團原料融合，以此作為雙自由基合成子，快速構建了傳統方法極難制備的各種類型螺環、橋接和取代飽和環。

所需原料的廣泛可及性實現了未開發化學空間區域的取樣。試劑控制自由基生成導致高度區域選擇性和立體特異性環化，可用于藥物支架的后期功能化，從而取代冗長的從頭合成。

▲ Abstract：

Heteroarenes are ubiquitous motifs in bioactive molecules, conferring favourable physical properties when compared to their arene counterparts. In particular, semisaturated heteroarenes possess attractive solubility properties and a higher fraction of sp3 carbons, which can improve binding affinity and specificity. However, these desirable structures remain rare owing to limitations in current synthetic methods. Indeed, semisaturated heterocycles are laboriously prepared by means of non-modular fit-for-purpose syntheses, which decrease throughput, limit chemical diversity and preclude their inclusion in many hit-to-lead campaigns. Herein, we describe a more intuitive and modular couple-close approach to build semisaturated ring systems from dual radical precursors. This platform merges metallaphotoredox C(sp²)–C(sp³) cross-coupling with intramolecular Minisci-type radical cyclization to fuse abundant heteroaryl halides with simple bifunctional feedstocks, which serve as the diradical synthons, to rapidly assemble a variety of spirocyclic, bridged and substituted saturated ring types that would be extremely difficult to make by conventional methods. The broad availability of the requisite feedstock materials allows sampling of regions of underexplored chemical space. Reagent-controlled radical generation leads to a highly regioselective and stereospecific annulation that can be used for the late-stage functionalization of pharmaceutical scaffolds, replacing lengthy de novo syntheses.

地球科學One Earth

A global timekeeping problem postponed by global warming

全球變暖推遲了全球計時問題

▲ 作者：Duncan Carr Agnew

▲ 鏈接：

https://www.nature.com/articles/s41586-024-07170-0

▲ 摘要：

時間與地球自轉的歷史聯系意味著世界標準時間（UTC）密切遵循地球自轉。由于旋轉速率不是恒定的，UTC包含不連續性（閏秒），這使其在計算機網絡中的使用變得復雜。自1972年以來，所有的UTC不連續點都需要增加一閏秒。

研究組通過衛星重力測量，證明格陵蘭島和南極洲冰層加速融化使地球自傳角速度比以前更快降低。從觀測到的角速度中去除這種影響表明，自1972年以來，地球液態核心的角速度一直在以恒定的速率下降，而地球其他部分的角速度穩步增加。

外推地核和其他相關現象的趨勢來預測未來地球定向表明，按照當前定義，到2029年，UTC將需要負一閏秒。這將給計算機網絡時間帶來前所未有的挑戰，并可能需要比計劃更早地去更改UTC。如果極地冰層最近沒有加速融化，這個問題將會提早3年發生：全球變暖已經影響到全球計時。

▲ Abstract：

The historical association of time with the rotation of Earth has meant that Coordinated Universal Time (UTC) closely follows this rotation. Because the rotation rate is not constant, UTC contains discontinuities (leap seconds), which complicates its use in computer networks. Since 1972, all UTC discontinuities have required that a leap second be added. Here we show that increased melting of ice in Greenland and Antarctica, measured by satellite gravity, has decreased the angular velocity of Earth more rapidly than before. Removing this effect from the observed angular velocity shows that since 1972, the angular velocity of the liquid core of Earth has been decreasing at a constant rate that has steadily increased the angular velocity of the rest of the Earth. Extrapolating the trends for the core and other relevant phenomena to predict future Earth orientation shows that UTC as now defined will require a negative discontinuity by 2029. This will pose an unprecedented problem for computer network timing and may require changes in UTC to be made earlier than is planned. If polar ice melting had not recently accelerated, this problem would occur 3 years earlier: global warming is already affecting global timekeeping.