反式錫鈣鈦礦太陽能電池中錫鈣鈦礦層(Tin Perovskite簡稱TPsk)是沉積在電洞傳遞層(Hole transport layer簡稱HTL)上，HTL的品質將會影響TPsk的沉積與品質。本研究以熱蒸鍍的方式製備WO3作為反式錫鈣鈦礦太陽能電池的HTL，WO3的價帶能(-5.33 eV)與本實驗所使用TPsk (FA0.98EDA0.01SnI3，價帶能為-5.57 eV)之能量差比PEDOT:PSS的價帶能(-5.15 eV)與TPsk之能量差小，因此以WO3為HTL時，電洞在元件內傳輸時的能量損失較少，所組裝元件有較大的開路電壓(Open circuit voltage，Voc)及光電轉換效率(Power conversion efficiency，PCE)，以WO3及PEDOT:PSS膜作為HTL所組裝元件的Voc分別為0.59 V和0.53 V，最高PCE則分別為9.44%及8.93%。WO3膜為HTL所組裝的元件在手套箱中經2520小時仍可維持原效率的84% ，而PEDOT:PSS膜為HTL所組裝的元件在相同保存條件下經2520小時僅維持原效率67%。而元件的熱穩定性測試中，WO3膜為HTL所組裝的元件在手套箱中加熱60C經2小時仍可維持原效率的72%，而PEDOT:PSS膜為HTL所組裝的元件在相同測試條件下僅維持原效率58%。WO3膜可經UV/O3後處理提高膜與TPsk前驅溶液的相容性，使沉積其上的TPsk品質變好，由SEM表面形貌圖可看見沉積在WO3的錫鈣鈦礦膜顆粒較大且平整。時間解析螢光光譜也顯示TPsk沉積在WO3膜上的載子生命週期比沉積在PEDOT:PSS上短，意味著WO3膜比PEDOT:PSS能更快速的將電洞由TPsk萃取出來並傳遞至陽極。;In inverted tin perovskite solar cells (referred as TPSCs), the tin perovskite layer (referred as TPsk) is deposited on top of the hole transport layer (referred as HTL). Therefore the quality of the HTL will be effected by the deposition methods and the quality of the resulting TPsk layer. In this study, WO3 prepared by thermal evaporation was used as an HTL for inverted tin perovskite solar cells. The valence band energy of WO3 (-5.33 eV) closer (compared to the generally used PEDOT:PSS with a valence band energy of -5.15 eV) to that of TPsk (FA0.98EDA0.01SnI3 with the valence band energy of -5.57 eV) used in this experiment. Therefor WO3 can be a better HTL than PEDOT:PSS. The Voc and PCE of TPSCs based on WO3 and PEDOT:PSS HTLs are 0.59 V and 0.53 V, 9.44% and 8.93% respectively. Without packing, the TPSC based on WO3 HTL can maintain 84% of the original efficiency after 2520 hours in the glove box, while that assembled with PEDOT:PSS HTL 33% of the original efficiency lost under the same test conditions. When the cells were heated at 60oC in a glove box, the TPSCs assembled with WO3 HTL can maintain 72% of the original efficiency after heating for 2 hours, while the TPSC based on PEDOT:PSS HTL can only maintain 58% of the original efficiency. SEM surface topography revealed that the tin perovskite grains deposited on WO3 are larger and flatter compared to those coated on top of PEDOT:PSS. Time-resolved photoluminescence spectroscopy also shows that the carrier lifetime of TPsk deposited on WO3 film is shorter than that deposited on PEDOT:PSS meaning that WO3 film can extract holes from TPsk and transfer to the anode more quickly than PEDOT:PSS.
