Fluolab【Adv.Mater.】苏州大学彭军、张晓宏等|26.77%效率突破！分子极化诱导协同界面工程助力高性能钙钛矿太阳电池
文章标题： Molecular Polarization-Driven Synergistic Interface Engineering for High-Performance Perovskite Solar Cells
通讯作者： Yi Ji, Xiao-Hong Zhang, Jun Peng
文章概要
引言
金属卤化物钙钛矿太阳电池凭借其优异的光电特性和低成本制备优势，已成为最具潜力的下一代光伏技术之一。在反式结构器件中，自组装单分子层（SAM） 因其能级匹配和高效空穴提取能力而备受青睐，但其在透明导电氧化物衬底上容易发生随机聚集，导致覆盖不均。此外，SAM末端基团的疏水性会降低钙钛矿前驱液的润湿性，进而引发界面空洞和严重的非辐射复合。尽管此前研究尝试过共同吸附或分子桥接等手段，但如何同时实现均匀的SAM分布和强力的界面化学键合，依然是提升器件效率与稳定性的核心难题。
Mechanistic insights into synergistic interface engineering driven by m-APCA. (a) Chemical structure and ESP distribution of the p-APCA and m-APCA molecules (red: positive potential; blue: negative potential). (b) The interaction configurations of p-APCA and m-APCA with Me-4PACz, respectively. The atomic configurations of (c) p-APCA and d) m-APCA interacting with the perovskite, along with (e) the corresponding calculated binding energy. (f) The XPS C 1s spectra of the Me-4PACz film with and without m-APCA treatment. (g) The UV–vis absorption spectra of Me-4PACz, p-APCA, and the mixture of p-APCA and Me-4PACz in methanol solutions. (h) The UV–vis absorption spectra of Me-4PACz, m-APCA, and the mixture of m-APCA and Me-4PACz in methanol solutions. The XPS (i) Pb 4f and (j) I 3d spectra of peeled-off buried perovskite films, with and without p-APCA or m-APCA treatment. (k) The 1H NMR spectra of FAI with and without m-APCA.
主要实验及结论
研究团队提出了一种分子极化驱动的协同界面工程策略，通过引入一种具有不对称双官能团的间位取代分子2-氨基嘧啶-4-羧酸（m-APCA） 来优化界面。理论计算和实验结果共同表明，m-APCA独特的不对称结构诱导了显著的电荷极化，其偶极矩高达5.04 D，远超对称结构的异构体。这种强极化效应不仅通过增强的π-π堆积作用抑制了SAM分子的聚集，确保了衬底的均匀覆盖，还通过其羧基锚定在FTO衬底上，有效填补了SAM层的物理缺陷。
Impact of synergistic interface engineering on the FTO/Me-4PACz Substrate. (a) KPFM and (b) C-AFM images of different FTO/Me-4PACz substrates, with and without p-APCA or m-APCA treatment. The relationship between the oxidative peak current and the voltage scan rate for (c) FTO/Me-4PACz, (d) FTO/Me-4PACz/p-APCA, and (e) FTO/Me-4PACz/m-APCA substrates; insets show the corresponding cyclic voltammograms in o-DCB solution at various scan rates. The (f) conductivity and (g) hole mobility comparison of different FTO/Me-4PACz substrates, with and without p-APCA or m-APCA treatment. (h) Energy level diagram of the Control, p-APCA and m-APCA-modified FTO/Me-4PACz substrates, and perovskite.
Impact of synergistic interface engineering on the perovskite thin film. (a) SEM images of the buried interfaces of perovskite films deposited on FTO/Me-4PACz w/wo p-APCA or m-APCA substrates. (b) PL mapping of the buried perovskite films peeled off from different FTO/Me-4PACz substrates, with and without p-APCA or m-APCA treatment. (c–e) The GIXRD patterns as a function of ω value from 0.3° to 1.5° for perovskite buried interface films grown on FTO/Me-4PACz substrates, with and without p-APCA or m-APCA treatment. (f) Linear fitting of 2_θ_-ω from GIXRD patterns with different instrumental ω values. (g) PL and (h) TRPL spectra of perovskite films deposited on FTO/Me-4PACz substrates, with and without p-APCA or m-APCA treatment, obtained under excitation from the perovskite surface.
在光电性能方面，m-APCA经过改性的衬底表现出更加显著的p型特征和更高的表面电势均匀性，极大地降低了界面处的空穴传输阻挡。通过非破坏性剥离技术观察发现，改性后的钙钛矿薄膜晶粒尺寸明显增大，且彻底消除了埋底界面处的空隙，形成了紧密的界面接触。瞬态荧光光谱和光致发光成像证实，该策略有效抑制了深能级缺陷引发的非辐射复合，使载流子寿命从148 ns显著延长至481 ns。
Influence of synergistic interface engineering on device stability. (a) Contact angles of the perovskite precursor on FTO/Me-4PACz and FTO/Me-4PACz/m-APCA substrates, measured after 10 s of wetting. XRD patterns of buried interface of (b) Control and (c) m-APCA-modified perovskite films aging in N2 under annealing at 85°C and corresponding (d) SEM images. (e) The long-term storage stability for the Control and m-APCA-modified devices. (f) MPP tracking of unencapsulated devices with and without m-APCA modification under continuous one-sun illumination in N2 environment.
基于此策略，研究团队在不同体系下均取得了突破性进展。小面积反式钙钛矿电池实现了26.77%（认证效率26.71%） 的极高能量转换效率，且器件滞后效应极低。在1.01平方厘米的大面积器件上，效率依然保持在26.08%，充分展示了该策略在工业化放大生产中的潜力。此外，该方法在1.65 eV的宽带隙器件中也获得了24.17%的高效率。
Influence of synergistic interface engineering on device stability. (a) Contact angles of the perovskite precursor on FTO/Me-4PACz and FTO/Me-4PACz/m-APCA substrates, measured after 10 s of wetting. XRD patterns of buried interface of (b) Control and (c) m-APCA-modified perovskite films aging in N2 under annealing at 85°C and corresponding (d) SEM images. (e) The long-term storage stability for the Control and m-APCA-modified devices. (f) MPP tracking of unencapsulated devices with and without m-APCA modification under continuous one-sun illumination in N2 environment.
总结及展望
该项研究不仅通过分子设计解决了反式钙钛矿电池长期存在的界面复合问题，更证明了分子极化在调控薄膜生长和电荷动力学中的关键作用。实验数据表明，未封装的器件在连续光照1200小时后，仍能保持96%的初始效率，展现出卓越的运行稳定性。这种通用的界面调控范式为实现高效、稳定的钙钛矿光伏组件提供了全新的思路，对推动钙钛矿太阳电池的商业化进程具有重要的指导意义。