三碘化鉛甲基銨之鈣鈦礦太陽能電池的穩定性研究

Abstract

在本博士論文的第一部分，三碘化鉛甲基銨 (MAPbI3，其中MA代表甲基銨) 鈣鈦礦太陽能電池（PVSCs）的穩定性透過以下方法進行仔細的檢測：氧化鋅-硫化鎘核殼 (ZnO@CdS) 奈米顆粒材料嵌入環氧樹脂膜（EP-ZC膜 具有不同比例的 CdS 殼層厚度，即 EP-ZC1、EP-ZC3 和 EP-ZC6）、元件封裝（玻璃片和紫外線固化凝膠）、以及在不同溫度條件下（10°C、室溫（無溫控）、65°C）進行測試。EP-ZC膜用於屏蔽短波長的太陽光線（紫外線、近紫外線、紫光和深藍光），這些短波長的光線會導致MAPbI3產生光降解，進而降低PVSCs的轉換效率（PCE）。此外，在連續500小時的光照測試中，也記錄了部分元件的外部量子效率（EQE）光譜、與電流密度（J）-電壓（V）的測量結果。此外，透過飛行時間-二次離子質譜法（TOF-SIMS）的分析，來定量比較有、無使用具有光遮蔽功能的EP-ZC膜之鈣態礦封裝元件因MAPbI3降解所產生的碘化物，分別在溫度10°C和65°C下之差異。EP-ZC6膜經10°C、連續500小時光浸潤後之封裝PVSCs元件中，仍維持了98%的初始元件效率，展現出最佳的保護效果。從本研究連續光照的研究結果中來看，我們可以優先考量濕度、溫度和光對PVSCs穩定性的影響。 而本論文的第二部分則集中在多晶和單晶的鈣態礦元件穩定性的比較分析。我們成功地透過擴散輔助空間限制生長法製備了單晶薄膜的鈣態礦元件。在短期元件穩定性的結果中揭示了無論是否使用EP-ZC6膜、或有無元件封裝，單晶鈣態礦元件的穩定性皆比多晶鈣態礦元件更為優良。這些發現指出，穩定、且高效的單晶鈣態礦元件，在產業邁向商業化過程中是一個很有前途的候選者。

In the first part of this Ph.D. thesis, the stability of MAPbI3-based (MA stands for methylammonium) perovskite solar cells (PVSCs) have been carefully examined by ZnO@CdS nanoparticle-embedded epoxy films (EP-ZC films with varying ratios of CdS shell layer thickness i.e., EP-ZC1, EP-ZC3, and EP-ZC6), device encapsulation (of glass sheet and UV-curing gel), and in different temperatures, 10 oC, room temperature (no temperature control), and 65 oC. EP-ZC films are used for shielding the short wavelength of the sunlight (UV, near UV, violet, and deep blue) which causes the photodegradation of MAPbI3 and hence the decline of power conversion efficiency (PCE) of PVSCs. Some external quantum efficiency (EQE) spectra of the device have been recorded alongside of the 500 hr continuous light soaking measurement of current density (J)voltage (V) of the devices. The time-of-flight secondary ion mass spectroscopy (TOF-SIMS) analysis has been performed for a quantitative comparison of the iodide derived from the degradation of MAPbI3 in the encapsulated devices with or without the light-shielding EP-ZC films at 10 oC and 65 oC, respectively. The EP-ZC6 film shows the best protection for encapsulated PVSCs with a 98% of the initial PCE at 10°C after 500 hr continuous light soaking. In this study, from the continuous light soaking results we can prioritize the moisture, temperature, and light in the influence of the stability of PVSCs. The second portion of the Ph.D. thesis is centered around a comparative analysis between the stability of polycrystalline and single crystal MAPbI3 PVSCs. We have successfully fabricated thin-film single crystal-based MAPbI3 PVSCs using the diffusion-assisted space-confined growth method. Short-term stability results with or without the EP-ZC6 film and with or without encapsulation reveal that single-crystal-based PVSCs are more stable than their polycrystalline counterparts. These findings indicate that single-crystal-based PVSCs are a promising candidate for stable and efficient PVSCs as the industry moves towards commercialization.