反式鈣鈦礦太陽能電池介面鈍化之結構分析

Abstract

本研究針對反式鈣鈦礦太陽能電池進行介面工程設計，藉由在鈣鈦礦表面熱蒸鍍碘化鉛後，施以苯乙胺類鹵化銨鹽處理，於其與電子傳輸層之間形成一層具結構穩定性的鈍化層，並探討其對元件表面形貌、晶體結構、光電特性與轉換效率的影響。研究核心目標為改善介面品質、降低非輻射複合，進而提升元件效能與操作穩定性。 實驗結果顯示，碘化鉛蒸鍍會造成表面空洞與粗糙，但經過苯乙胺類鹽類後處理可重新組織表面結構，並生成具方向性的六方相δ-FAPbI₃，其晶格排列與下層鈣鈦礦相容，有助於提升介面連續性與缺陷鈍化。光電分析指出，修飾處理雖未改變主體吸收邊與能隙，但可顯著提升螢光強度與載子壽命，並調整能階排列，有利於載流子選擇性與傳輸效率。 元件測試顯示，經介面修飾後元件之開路電壓與功率轉換效率顯著提升，由原本21%提升至接近24%，其中以氯化苯乙胺修飾效果最佳。量子效率與電致發光結果進一步證實輻射效率提升與電壓損失下降。穩定性測試亦顯示，修飾後元件在常溫與高溫條件下均可維持良好性能。 綜合而言，本研究提出一種實用且具延展性的介面修飾策略，透過相變誘導與分子配位作用改善埋藏介面之結構與能階分佈，進而提升鈣鈦礦太陽能電池之效率與穩定性，展現應用潛力。

This study investigates interfacial engineering in inverted perovskite solar cells through the formation of a δ-FAPbI₃-based passivation layer on the perovskite surface, formed by sequential PbI₂ evaporation and phenethylammonium halide (PEAX, X = Cl, Br, I) treatment, enabling mild surface reconstruction without damaging the bulk film. Structural analyses reveal that δ-FAPbI₃ adopts an oblique orientation inherited from the underlying perovskite, improving lattice continuity at the buried interface. Optical and electronic characterizations confirm suppressed non-radiative recombination, enhanced photoluminescence, prolonged carrier lifetimes, and favorable energy alignment, while the bulk bandgap remains unchanged. Device measurements show that PEAX treatment increases open-circuit voltage (VOC) and raises power conversion efficiency (PCE) from 21% to nearly 24%, with PEACl yielding the best results. Photoluminescence and electroluminescence analyses further confirm enhanced radiative efficiency and reduced voltage loss. Stability tests indicate over 95% efficiency retention under ambient conditions and around 85% under thermal stress. This work presents a practical interfacial strategy that enables structural and energetic optimization at the buried interface, offering a promising route to high-efficiency and stable inverted perovskite solar cells.