| 摘要: | 目前反式錫鈣鈦礦太陽能電池(Tin Perovskite Solar Cells, TPSCs)最常使用的電洞傳遞層(Hole Transport Layer, HTL)為PEDOT:PSS，因其具高光穿透度和高導電度而被廣泛採用，然而，PEDOT:PSS的電洞遷移率偏低(約為10-4 cm2V-1s-1)，容易影響組裝成元件的電洞傳輸效率。近年來學者開發具不受水氣影響、跟鈦礦能階匹配和高電洞遷移率等優點的無機電洞傳遞層(例如：NiOx、CuO和SnOx等)並應用於PSCs中。本研究期望透過結合兩者的優勢進而提高其應用於TPSC時的光電轉換效率，因此在FTO導電玻璃及PEDOT:PSS間引入一層CuO作為反式錫鈣鈦礦太陽能電池的雙電洞傳遞層(CuPE)。雖然CuPE膜在300-1000 nm的平均光穿透度(82%)略低於PEDOT:PSS膜(84%)，但其Valence Band(VB)能從-5.01降低至-5.13 eV，使其與錫鈣鈦礦的VB更加匹配，有助於減少電洞傳遞時的能量損失。此外，CuPE膜的導電度(7.10×10-2 S/cm)高於CuO膜及PEDOT:PSS膜(4.02×10-2及2.49×10-2 S/cm)，且電洞遷移率(6.21*10-4 cm2V-1s-1)也高於CuO膜及PEDOT:PSS膜(2.76*10-4及1.49*10-4 cm2V-1s-1)，有助於將電洞更快速地傳遞至外線路。此外，以FPEABr作為界面層(HTL/PSK)藉由PEA+來填補鈣鈦礦底部陽離子空位，間接減少Sn4+的比例。而錫鈣鈦礦沉積在CuPE膜上的(100)晶面強度最強且缺陷密度最低顯示錫鈣鈦礦膜的品質最好，而螢光強度最弱也暗示CuPE能更有效地將錫鈣鈦礦中的電洞萃取出來。以CuPE、CuO及PEDOT:PSS三種HTLs所組裝元件的最高光電轉換效率分別為9.91%、8.72%及8.65%。而以CuPE作為電洞傳遞層之元件在未封裝下放置於手套箱中，經1584小時後，仍可維持原效率的82%；在相同測試條件下，以CuO及PEDOT:PSS作為電洞傳遞層之元件分別僅維持原效率的63%及69%。;Currently, the most commonly used hole transport layer (HTL) in inverted tin-based perovskite solar cells (Tin Perovskite Solar Cells, TPSCs) is PEDOT:PSS, due to its high optical transmittance and good electrical conductivity. However, PEDOT:PSS has a relatively low hole mobility (~10⁻⁴ cm²V⁻¹s⁻¹), which may limit hole transport efficiency in fabricated devices. In recent years, researchers have developed inorganic HTLs such as NiOx, CuO, and SnOx, which exhibit advantages such as moisture resistance, better energy level alignment with the VB of tin perovskite, and high hole mobility, and have applied them to perovskite solar cells (PSCs). This study aims to combine the advantages of both organic and inorganic HTLs to improve the power conversion efficiency (PCE) of TPSCs by introducing a CuO layer between the FTO conductive glass and PEDOT:PSS, forming a bilayer HTL structure (CuPE). Although the average optical transmittance of the CuPE film in the 300–1000 nm range (83%) is slightly lower than that of the PEDOT:PSS film (85%), its valence band (VB) shifts from −5.01 eV to −5.13 eV, achieving better energy level alignment with the VB of tin perovskite. This alignment helps to reduce energy loss during hole transport. In addition, the CuPE film demonstrates a higher conductivity(7.10 × 10⁻² S/cm) than both the CuO and PEDOT:PSS films (4.02 × 10⁻² and 2.49 × 10⁻² S/cm, respectively). Moreover, the hole mobility of the CuPE film (6.21 × 10⁻4 cm²V⁻¹s⁻¹) is also significantly higher than that of CuO (2.76 × 10⁻4 cm²V⁻¹s⁻¹) and PEDOT:PSS (1.49 × 10⁻4 cm²V⁻¹s⁻¹), which facilitates more efficient hole transport to the external circuit. In addition, using FPEABr as an interfacial layer (HTL/PSK) can help fill the A-site cation vacancies at the bottom of the perovskite layer through its PEA+, thereby indirectly reducing the proportion of Sn⁴⁺. The perovskite films deposited on the CuPE layer exhibit the strongest (100) crystal orientation and the lowest defect density, indicating that the tin perovskite film on CuPE possesses superior crystallinity and overall quality. The lowest photoluminescence intensity also suggests that CuPE enables more efficient hole extraction from the tin perovskite layer. Devices fabricated using CuPE, CuO, and PEDOT:PSS as HTLs achieved maximum PCEs of 9.91%, 8.72%, and 8.65%, respectively. Moreover, under unencapsulated storage in a glove box for 1584 hours, the CuPE-based device retained 82% of its initial efficiency, outperforming CuO and PEDOT:PSS devices, which retained only 63% and 69%, respectively, under the same testing conditions. |
