本研究以自旋幫浦技術探討 Bi2Te3/WSe2 雙層膜之自旋-電荷轉換特性，並與Bi2Te3 薄膜交叉比較；Bi2Te3 作為傳統拓樸絕緣體具有強自旋軌道耦合與拓樸表面態等物理特性，WSe2 做為二維材料則具強自旋軌道耦合與Rashba 介面態，由於兩者皆為凡得瓦層狀材料，其表面缺乏懸掛鍵（dangling-bond-free surface），因此可透過凡得瓦力（van der Waals force）形成原子尺度清晰且電子結構明確的異質介面（atomically clean and electronically sharp interface）。此異質結構利於探討拓樸表面態與 Rashba 介面態之交互作用（interplay）對轉換效率之影響。
本研究以分子束磊晶製備不同厚度之 Bi2Te3 與 Bi2Te3/WSe2(1ML)，利用 Raman、RHEED、XRD、XRR、AFM 與 XPS 分析薄膜品質與介面特性；Raman、AFM與RHEED結果顯示，WSe2 具有單層、晶體品質(high crystalline quality)和平整表面(smooth surface)以利於後續異質結構磊晶。XRD與XRR結果顯示Bi2Te3 及 Bi2Te3/WSe2 皆呈現良好結晶性、c 軸優選取向與可控厚度；AFM與RHEED 顯示 Bi2Te3 具有層狀成長特徵、高晶體品質(high crystalline quality)和平整表面(smooth surface )；XPS depth mapping則確認介面間 Bi–Te 與 W–Se 鍵結訊號，且未觀察到明顯 Bi-Se鍵結，顯示介面未發生顯著化學混層。
自旋幫浦量測結果顯示，單層 Bi2Te3 具有明顯自旋-電荷轉換行為，且 λIEE 呈厚度依賴性，其中 8 nm Bi2Te3 具有最高轉換效率，λIEE 約為 0.92 nm。相較之下，Bi2Te3/WSe2 異質結構之整體 λIEE 低於單層 Bi2Te3，8 nm 樣品約為 0.43 nm，下降約 53%。此結果顯示 WSe2 引入之 Rashba 介面態未有效增強轉換效率，可能因其與 Bi2Te3 拓樸表面態之自旋極化貢獻相互抵消，導致轉換效率受到抑制。

The spin-to-charge conversion properties of Py/Bi2Te3 thin films and Py/Bi2Te3/WSe2 heterostructures were investigated by room-temperature spin pumping. Raman, RHEED, XRD, XRR, AFM, and XPS analyses confirmed the crystalline quality, c-axis orientation, thickness control, surface morphology, and chemical bonding of the samples. AFM revealed layered Bi2Te3 growth with a step height of about 1 nm, corresponding to one quintuple layer, while depth-resolved XPS verified Bi–Te and W–Se bonding without obvious Bi–Se formation. Spin pumping measurements showed that Py/Bi2Te3 exhibited the highest inverse Edelstein length (λIEE) of 0.92 nm at 8 nm.
In Py/ Bi2Te3/ WSe2, λIEE decreased to about 0.43 nm at 8 nm, indicating that WSe2-induced Rashba interfacial states destructively couple with Bi2Te3 topological surface states and suppress spin-to-charge conversion

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