最新Acc. Mater. Res：有机 Amidiniums在钙钛矿光伏材料中的作用|perovskite|top|光伏材料|太阳能电池|钙钛矿|阳离子

主要内容：

清洁能源作为可持续发展的基石，在光伏技术中，尤其是基于有机-无机铅卤化物钙钛矿（OLHPs）材料的太阳能电池，近年来取得了显著的突破性进展。OLHPs的化学式为ABX3，其中A位阳离子的选择对于钙钛矿结构的稳定性和整体光电性能具有至关重要的影响。随着研究的不断深入，超大尺寸Amidiniums（作为一类特殊的A位阳离子）作为添加剂或钝化剂，在OLHPs中展现出了其独特且不可或缺的作用。

在本文中，西湖大学工学院王睿教授及其团队深入探讨了Amidiniums在OLHPs研究中的关键进展。这些进展不仅从热力学和动力学的角度揭示了Amidiniums对成核与结晶过程的精细调控机制，还深入分析了其对体相和界面电子态的调制效应。具体而言，Amidiniums通过优化OLHPs的成核过程，显著提升了结晶质量，并深刻影响了电子构型。同时，它们还能通过应变诱导效应精确调控体相电子态，并通过诱导形成低维相和多功能基团来调节表面电子态，从而有效消除了表面电势的不均匀性，进一步提高了太阳能电池的光电转换效率和长期稳定性。

此外，该研究团队还通过对比分析不同厚度的钙钛矿薄膜，揭示了应力、电导率、载流子迁移率和浓度之间的复杂关系，并提出了一种创新的应变释放策略（SRS）来有效减轻厚膜中的应变，进而提升器件性能。引入大尺寸Amidiniums不仅通过晶格膨胀显著改善了热载流子的弛豫过程，还显著提升了太阳能电池的光电转换效率。在界面工程方面，Amidiniums钝化技术成功形成了特殊的低维相，有效解决了由表面电势不均匀引起的降解问题，从而进一步提升了PSC（钙钛矿太阳能电池）的性能。同时，具有特定功能基的钝化层还有效抑制了外来离子的注入，为PSC的长期稳定性提供了有力保障。

综上所述，Amidiniums在OLHPs研究中的作用不容忽视。它们在增强钙钛矿结晶动力学、调节电子态以及提高PSC效率和稳定性方面发挥着至关重要的作用。随着钙钛矿太阳能电池逐步迈向商业化应用，Amidiniums有望在制备大面积、均匀且高质量的钙钛矿薄膜方面发挥关键作用，为解决太阳能电池和组件的长期运行不稳定性挑战提供新的解决方案。未来，新Amidiniums发现或新颖应用的出现，将进一步推动OLHPs及其相关光电器件的蓬勃发展，为清洁能源的广泛应用贡献力量。

Figure 1.(a) History of record PSCs performance and main A cation compositions that were used.(1,2)(b) Molecular structures of the reported organic ammoniums.

Figure 2.(a) Schematic representation illustrating the thermodynamic driving forces and kinetics underlying the oriented nucleation of perovskite films. (b) In situ GIXRD analysis of perovskite films fabricated without PAD (top) and with PAD (bottom), highlighting the transition through the nucleation and growth stages, where N++0marks the nucleation initiation, Nsrepresents the nucleation stage, and G corresponds to the growth stage. The intensity is represented on a black-red color scale (arbitrary units). (c) Azimuthal angle evolution during the nucleation stage, comparing films without PAD (top) and with PAD (bottom), illustrating the differences in crystallographic orientation. (d) Photoluminescence (PL) spectra evolution during nucleation for films without PAD (top) and with PAD (bottom), demonstrating enhanced structural uniformity with PAD. Reproduced with permission from ref+++++(9). Copyright 2023 The Author(s), under exclusive license to Springer Nature Limited.

Figure 4.(a) Schematic illustration of the hot phonon bottleneck effect, highlighting the accumulation of hot phonons and their influence on carrier cooling dynamics. (b) Carrier temperatures for perovskites doped with FA, higher BZM, and PLM concentrations, extracted using the Boltzmann model, revealing variations in carrier cooling efficiency among the compositions. (c) Intrinsic electron–phonon scattering times for these perovskite materials, illustrating differences in electron–phonon coupling strength and its impact on carrier relaxation processes. Reproduced with permission from ref+++(13). Copyright 2024 AIP Publishing LLC.

Figure 5.(a) Locations of Li cations above and below the perovskite surface, as determined by first-principles calculations, showing the effect of the MSBZM layer on cation distribution. (b) Calculated energy barrier for Li migration, illustrating the significant increase in migration resistance with the MSBZM layer. (c) Secondary ion mass spectrometry (SIMS) analysis of PSCs without and with MSBZM treatment, highlighting differences in ion migration. (d) Depth profiles of Li ions in control and MSBZM-treated perovskite films, demonstrating reduced Li-ion migration in treated films. (e) PCE tracking of unencapsulated control and MSBZM-treated devices at 60 ± 5 °C in a nitrogen-filled glovebox, with error bars indicating the standard deviation across four devices per condition. (f) MPP tracking under 1-sun illumination at 50 ± 5 °C, showing the improved stability of MSBZM-treated devices. Reproduced with permission from ref+++++++(17). Copyright 2024 American Chemical Society.