由二硫過渡金屬二維層組成的范德華異質結構最近已經成為一類新的材料。理論預測,二硫過渡金屬堆疊形成的異質結構二型半導體異質結構,有利於有效電子-電洞分離。據報導,二硫化鎢 / 二硫化鉬異質結構僅在50飛秒內發生超快電洞轉移。 在本論文中,我們將二硫化鎢 / 二硫化鉬異質結構整合到有機太陽能電池作為空穴轉移層。透過化學剝離,我們可以得到幾層和單層二硫過渡金屬奈米片的溶液。運用這些溶液,可以達到溶液製程的電洞傳輸層。我們發現基於二硫化鎢 / 二硫化鉬電洞傳輸層的元件的能量轉換效率大於基於二硫化鎢和二硫化鉬電洞傳輸層的元件的能量轉換效率。改善的效率表示著對於載子的收集是更有效。此外,基於二硫過渡金屬(二硫化鎢、二硫化鉬和二硫化鎢/二硫化鉬)電洞傳輸層的元件,由於其化學惰性,他們被儲存在大氣下是高度穩定的。
Van der Waals heterostructures composed of two-dimensional transition metal Dichalcogenides (TMDs) layers have recently emerged as a new class of materials, where quantum coupling between stacked atomically thin two-dimensional layers. Theory predicts that stacked TMDs heterostructures form type II semiconductor heterojunctions that facilitate efficient electron-hole separation for light harvesting. It has been reported that ultrafast hole transfer occurs in WS2/MoS2 heterostructure only within 50 fs. In this thesis, we integrate the WS2/MoS2 heterostructure into organic solar cells as hole transfer layer (HTL). By chemically exfoliation, we can get the solution of few-layers and monolayers TMDs nanosheets. With these solutions, solution-processed HTLs can be achieved. We found that power conversion efficiency of the device based on WS2/MoS2 HTL is large than the ones based on WS2 and MoS2 HTLs. The improved performance of devices indicates that carrier collections are more efficient. Besides, the devices based on TMDs (WS2, MoS2, and WS2/MoS2) HTLs were highly stable while they were stored in ambient air due to their chemical inert.