Figure 1. a) Electrostatic potential mapping of SPA molecule and schematic diagram of deliberate design of SPA as modification layer between the TiO₂ and perovskite buried interface. b) The survey XPS spectra of control and target TiO₂ films. c) S 2p, d) K 2p, e) Ti 2p, and f) O 1s core-level XPS spectra of control and target TiO₂ films. g) FTIR spectra of control and target TiO₂ as well as pure SPA powder in the wavenumber range of 600–1250 cm⁻¹.

Figure 2. Surface topographic SEM images of a) control and b) target TiO₂ films. Corresponding EDS mapping of c) S element and d) K element for target TiO₂ films. e) Optical transmittance spectra of FTO and different FTO/TiO₂ films. f) Conductivity measurements for control and target TiO₂ employing the four-probe method. g) Electron mobility measurements of control and target TiO₂ deposited on FTO substrates. h) The optimized geometries of C=O and−SO₃⁻ in SPA molecules adsorption on TiO₂ surface, where the brown, gray, light pink, pink, yellow, and blue atoms represent the C, O, H, K, S, and Ti atoms, respectively.

Figure 3. Top-view SEM images of perovskite films deposited on a) control and d) target TiO₂ substrates. AFM images of perovskite films depos-ited on b) control and e) target TiO₂ substrates. GIWAXS patterns of perovskite films deposited on c) control and f) target TiO₂ at an incident angle of 0.3°. g) XRD spectra of different perovskite films. h) UPS spectra of different TiO₂ films. i) Schematic illustration of energy level diagram of different layers.

Figure 4. a) UV–vis absorption spectra of perovskite films deposited on control and target TiO₂ substrates. b) Representative absolute PL spectra of samples with different structures illustrated through glass side. c) PLQY values of samples with different structures illustrated through glass side. Inset: the corresponding ΔQFLS values. d) TRPL decays measured at a fluence of 3.1 µJ/cm² using pulsed (1 MHz repetition rate) excitation at 445 nm. The solid curves are double-exponential fits to the decays. e) The differential lifetime τ_diff calculated for the TRPL decays at a fluence of 3.1 µJ/cm2. f) EIS spectra of control and target photovoltaic devices under the dark conditions. g) The optimized structures of C=O, −SO₃⁻, and K⁺ in SPA molecules adsorption on CsPbI₃ surface, where the brown, gray, light pink, pink, yellow, green, black, and purple atoms, respectively, represent the C, O, H, K, S, Cs, Pb, and I atoms.

Figure 5. a) J–V curves of champion devices with or without SPA modification. b) Steady-state photocurrent at the maximum power point under AM 1.5G one sun illumination. c) EQE and integrated current density spectra of target devices. d) TPC and e) TPV curves of control and target devices. f) Statistical diagram of energy loss. g) Comparison of the VOC loss for CsPbI₃-based PSCs reported so far. h) XRD patterns of the perovskite films exposed to a controlled relative humidity of 25 ± 5%. i) Evolution of the normalized PCE for the unencapsulated devices under conditions of 25 ± 5% RH and 25 ± 5 °C.

   尽管CsPbI₃钙钛矿由于其优异的热稳定性在光伏领域显示出巨大的潜力，但严重的光电压损失严重制约了器件性能。掩埋的氧化钛/钙钛矿界面在界面电荷传输和钙钛矿结晶中起着关键作用，这与非辐射复合引起的开路电压损失密切相关。鉴于此，2022年11月17日北京科技大学康卓＆张跃院士团队于AM刊发通过埋底界面改性来推动CsPbI₃钙钛矿太阳能电池开压损失的极限的研究成果，特意使用具有特殊官能团的目标分子3-磺酸丙基丙烯酸钾盐来修饰掩埋界面，在钝化界面缺陷、优化能量排列和促进钙钛矿结晶方面产生有利的功能。实验表征和理论计算表明，掩埋界面修饰抑制了电子转移势垒，同时提高了钙钛矿晶体质量，从而减少了陷阱辅助电荷复合和界面能量损失。因此，对掩埋界面的全方位修饰，器件获得了20.98%的令人印象深刻的效率，实现了0.451V的创纪录低开压损失。所提出的掩埋界面修改策略提供了一个通用的方法来推动开压损失的极限，显示出开发高性能全无机钙钛矿光伏电池的广阔前景。

原文：https://onlinelibrary.wiley.com/doi/10.1002/adma.202207172