太赫兹时域光谱作为有机卤化物钙钛矿太阳能电池通用缺陷指纹识别工具
Terahertz Time-Domain Spectroscopy as a Universal Defect Fingerprinting Tool for Organic Halide Perovskite Solar Cells
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中文总结 AI 辅助
研究针对有机卤化物钙钛矿太阳能电池与理论效率的差距，利用太赫兹时域光谱技术，能在室温下对特定缺陷物种定量表征，以MAPbI3为例建立振子强度与缺陷浓度关系，还提出三支柱框架提高电池效率。
中文摘要 AI 辅助
有机-无机杂化钙钛矿（OHP）的单结功率转换效率（PCE）已超过26%，钙钛矿-硅串联电池效率超过34%，但与肖克利-奎塞尔（S-Q）极限仍有差距，主要因晶界（GB）缺陷导致非辐射复合、离子迁移和降解。传统探针无法识别和量化相关薄膜中的特定缺陷物种，而太赫兹时域光谱（THz-TDS，0.3 - 3.0 THz）能满足此需求。通过顺序真空蒸发（SVE）制备的四种OHP成分（MAPbI3、MAPbBr3、FAPbI3和CsPbI3），太赫兹光谱窗口可捕获本征声子模式和GB局部分子缺陷振动，实现室温下特定物种的定量表征。以MAPbI3中1.58 THz吸收为例，其振子强度与XPS量化的CH3NH2缺陷浓度呈线性关系，证明THz-TDS是直接、无损的缺陷测量仪。在此基础上，提出太赫兹引导缺陷工程的三支柱框架：通过振子强度分析进行定量缺陷测量；从系统构建的太赫兹库中识别材料特定指纹；通过实时反馈进行指纹引导的缺陷消除，共同定义了一个闭环质量控制循环，将光谱诊断与钝化策略相连，最终提高太阳能电池效率。
英文摘要
Organic-inorganic hybrid perovskites (OHPs) deliver certified single-junction power conversion efficiencies (PCEs) exceeding 26% and perovskite-silicon tandem values surpassing 34%, yet a substantial gap with the Shockley-Queisser (S-Q) limit persists-primarily due to grain-boundary (GB) defects that drive non-radiative recombination, ion migration, and degradation. Rational passivation demands a non-contact tool capable of identifying and quantifying specific defect species in device-relevant thin films, a capability absent from conventional probes. This short review demonstrates that terahertz time-domain spectroscopy (THz-TDS, 0.3-3.0 THz) fulfills this role. Across four OHP compositions fabricated by sequential vacuum evaporation (SVE)-MAPbI3, MAPbBr3, FAPbI3, and CsPbI3-the THz spectral window captures both intrinsic phonon modes and GB-localized molecular defect vibrations, enabling species-specific, quantitative characterization at room temperature. Notably, the oscillator strength of the SVE-specific 1.58 THz absorption in MAPbI3 scales linearly with XPS-quantified CH3NH2 defect concentration, establishing THz-TDS as a direct, non-destructive defect meter. Building on these findings, we propose a three-pillar framework for THz-guided defect engineering: (I) quantitative defect measurement via oscillator-strength analysis, (II) material-specific fingerprint identification from a systematically constructed THz library, and (III) fingerprint-guided defect elimination with real-time feedback-together defining a closed-loop quality-control cycle that connects spectroscopic diagnosis to passivation strategy and, ultimately, to enhanced solar-cell efficiency.
