鈣鈦礦量⼦點塔米電漿極化⼦由強耦合⾄元件實現

Abstract

Tamm 電漿子（TPs）微共振腔結構因其在金屬–介電質界面形成的超小有效模態體積與強電場侷限特性，提供了一個在室溫下實現強光–物質耦合的理想平台。本研究將單層全無機鈣鈦礦量子點（CsPbBr₃ QDs）嵌入 TP 微腔中，系統性地從基礎極化子物理出發，逐步推展至功能性光電元件之實現，涵蓋三項相互關聯之研究成果。(1) 研究於嵌入單層 CsPbBr₃ QDs 之 TP 微腔中，在室溫條件下驗證激子極化子的形成。將亞波長厚度之 QD 單層嵌入TPs 共振模態之超小有效模態體積，使光子–激子耦合強度大幅提升，獲得 ℏΩ=127.5 meV 之 Rabi 分裂能，遠超強耦合閾值。同時，透過調控 PMMA 緩衝層厚度，可系統性地改變激子–光子失諧量，進而調控極化子之色散關係。偏振分辨量測結果顯示，圓偏振與線偏振激發下之極化子–極化子交互作用常數分別為 gc~8.7ueV um²與gL~4.1 ueV um²，確立本平台作為室溫極化子自旋光子學之可行基礎。(2) 研究利用 TP 共振增強之電場侷限效應，實現以 CsPbBr₃ QD 為基礎之無色彩濾光片影像感測器。將 TPs 本徵模態與 QDs 激子吸收峰進行光譜匹配，可獲得光學吸收率 14 倍之提升，最大光響應度達 20.61 mA W⁻¹，且 TP 結構固有之波長選擇性使傳統色彩濾光片得以省略。採用 Bayer 濾光片陣列設計涵蓋 λ = 480、520 及 550 nm 三種共振波長，驗證多像素彩色影像感測之可擴展性。此外，引入 PMMA 載子捕捉中間層賦予元件神經形態突觸可塑性，並透過 64×64 光偵測器陣列模擬人臉辨識，辨識率超過 80%。(3)研究實現首個基於單層鈣鈦礦 QD TP 微腔之室溫電驅動激子極化子發光二極體。ℏΩ=124.3 meV 之 Rabi 分裂與 Fp=3.44 之 Purcell 增強因子，確認電驅動操作下之強耦合與腔體增強自發輻射。動量分辨電激發光映射提供電注入下極化子色散之直接實驗證據。相較於光激發下瓶頸效應隨泵浦功率逐漸消除，電注入下極化子瓶頸效應持續存在，指出載子熱化為邁向電驅動極化子凝聚之關鍵瓶頸。三項研究成果共同確立了嵌入單層 CsPbBr₃ QDs 之 Tamm 電漿子微腔作為多功能、可擴展且與製程相容之整合平台，涵蓋室溫極化子物理、共振增強感測及電驅動發光等應用領域，為未來室溫極化子雷射、自旋極化光源及神經形態光子電路之發展奠定堅實基礎。

Tamm-plasmon (TPs) microcavities, with their ultrasmall mode volumes and strong field confinement at the metal–dielectric interface, provide an ideal platform for room-temperature strong light–matter coupling. Here, a single monolayer of CsPbBr₃ quantum dots (QDs) is embedded in a TP microcavity, with the study progressing from fundamental polariton physics to functional optoelectronic devices across three interrelated contributions. (1) Room-temperature exciton-polariton formation is first demonstrated, with the subwavelength QD monolayer coupled to the TP's ultrasmall mode volume yielding a Rabi splitting of ℏΩ=127.5 meV, well above the strong-coupling threshold. Tuning the PMMA spacer thickness varies the exciton–photon detuning and thus the polariton dispersion, while polarization-resolved measurements give polariton–polariton interaction constants of gc~8.7ueV um² (circular) and gL~4.1 ueV um² (linear), establishing this platform for room-temperature polariton spin photonics. (2) The TP-enhanced field confinement is then used to realize a color-filter-free CsPbBr₃ QD image sensor: tuning the TP mode to the QD exciton absorption peak gives a 14-fold absorption enhancement and a maximum responsivity of 20.61 mA W⁻¹, while the TP's intrinsic wavelength selectivity removes the need for conventional color filters. A Bayer-pattern TP array (λ = 480, 520, 550 nm) validates scalable multi-pixel color sensing, and a PMMA charge-trapping layer adds neuromorphic synaptic plasticity, enabling facial recognition via a 64x64 photodetector array with over 80% accuracy. (3) Finally, the first room-temperature, electrically driven exciton-polariton LED based on this platform is realized, showing a Rabi splitting of ℏΩ=124.3 meV and a Purcell factor of Fp=3.44 that confirm strong coupling and cavity-enhanced emission under electrical operation. Momentum-resolved electroluminescence directly reveals the polariton dispersion under electrical injection, and unlike optical excitation—where the polariton bottleneck relaxes with pump power—it persists electrically, identifying carrier thermalization as the key barrier to electrically driven polariton condensation. Together, these results establish the CsPbBr₃ QD-embedded TP microcavity as a scalable, process-compatible platform spanning room-temperature polariton physics, resonance-enhanced sensing, and electrical light emission, laying groundwork for future polariton lasers, spin-polarized sources, and neuromorphic photonic circuits.