標題: 含噻吩與苯環之多環平面梯狀分子於高效能高分子太陽能電池之應用
Ladder-type multicyclic structures consisting of thiophene and benzene units for efficient polymer solar cells
作者: 陳秋翔
Chen, Chiu-Hsiang
許千樹
Hsu, Chain-Shu
應用化學系碩博士班
關鍵字: 低能隙高分子;太陽能電池;共軛高分子;梯狀分子;Low band-gap polymer;Solar cell;conjugating polymer;Ladder- type molecule
公開日期: 2011
摘要: 我們成功的設計和合成出三種含噻吩與苯環之多環平面梯狀分子diindeno[1,2-b:2’,1’-d]thiophene (DIDT) 、thienyl- phenylene-thienylene-phenylene-thienyl (TPTPT) 以及dithienocyclopentathieno[3,2-b]thiophene (DTCTT),此三種分子結構是利用碳原子將鄰近的噻吩與苯環或噻吩與噻吩間以共價鍵的方式連結起來,形成含有環戊二烯之五環、九環以及六環平面梯狀分子。 具有剛硬且平面性之電子施體 Br-DIDT、Bronic-DIDT、Br-TPTPT、Sn-TPTPT以及Sn-DTCTT與不同的電子受體 benzothiadiazole (BT)、4,7-di(thiophen-2-yl)benzothiadiazole (DTBT)、pyrrolopyrroledione (DPP)、thienopyrroledione (TPD) 以及phenanthrenequnioxaline (PQX) 在鈀金屬的催化下進行 Suzuki 偶合或Stille 偶合聚合反應,即可成功合成出交替型共軛高分子PDIDTBT、PDIDTDTBT、PTDIDTTBT、PTPTPTBT、PTPTPTDPP、PDTCTTTPD、PDTCTTBT以及PDTCTTPQX與隨機型共軛高分子PTPTPTBT11、PTPTPTBT12、PTPTPTDPP11、PTPTPTDPP12以及PTPTPTDPP13。交替型共軛高分子材料的優勢在於其結構是由電子施體與電子受體交替而成,在排列上較為規則,因此會有較好的堆疊,可有效增進電荷遷移率以達較高光電流之特性;而隨機型共軛高分子材料的優勢則在於可藉由控制電子施體與電子受體比例的不同,來調整分子內電荷轉移的效應,藉此增加光學吸收的強度以達到較理想的吸收特性。 比較此三種不同的電子施體後,以九環平面梯狀分子TPTPT系列的共軛高分子因併有剛硬且高平面性之 TPTPT ,並於濕式製程上具有理想的溶解度,且擁有適當的HOMO、LUMO能階及低能隙、高電荷遷移率,其元件光電轉換效率有超過4 %。在隨機型共軛高分子中以搭配電子受體DPP所得到的PTPTPTDPP12以及PTPTPTDPP13為最佳;而在交替型共軛高子中,以搭配電子受體BT所得到的高分子PTPTPTBT為最佳。 此三支共軛高分子材料皆應用於正結構以及反結構太陽能電池上。隨機型共軛高分子PTPTPTDPP12與PTPTPTDPP13在正結構元件效率可達到4.3%與4.1%;而在反結構元件上效率則提升至5.1%與4.6%。另外,交替型共軛高分子PTPTPTBT應用到正結構元件上,其效率可達到5.3%;當將其應用於反結構元件上,其效率更高達5.9%,是目前在反式有機太陽能電池中少數效率接近6%以上的元件結果。
We have successfully designed and synthesized ladder-type multifused diindeno[1,2-b:2’,1’-d]thiophene (DIDT) 、thienyl- phenylene-thienylene-phenylene-thienyl (TPTPT) units where each thiophene ring is covalently fastened with the adjacent benzene rings by a carbon bridge, forming two and four cyclopentadiene rings embedded in pentacyclic and nonacyclic structures. Another is dithienocyclopentathieno[3,2-b]thiophene (DTCTT) unit where thieno[3,2-b]thinophene (TT) ring is covalently fastened with the adjacent thiophene rings by a carbon bridge, forming two cyclopentadiene rings embedded in a hexacyclic structure. The rigid and coplanar Br-DIDT、Bronic-DIDT、Br-TPTPT、Sn-TPTPT and Sn-DTCTT building block were copolymerized with electron-deficient acceptors, benzothiadiazole (BT), 4,7-di(thiophen-2-yl)benzothiadiazole (DTBT), pyrrolopyrroledione (DPP), thienopyrroledione (TPD) and phenanthrenequnioxaline (PQX) via Suzuki or Stille polymerization. A new class of random and alternating copolymers PDIDTBT, PDIDTDTBT, PTDIDTTBT, PTPTPTBT11, PTPTPTBT12, PTPTPTDPP11, PTPTPTDPP12, PTPTPTDPP13, PTPTPTBT, PTPTPTDPP, PDTCTTTPD, PDTCTTBT and PDTCTTPQX with suitable optical and electronic properties were prepared. PTPTPTDPP12, PTPTPTDPP13 and PTPTPTBT copolymers incorporating this rigidified and coplanar TPTPT units simultaneously possess excellent solubilities for solution-processability, low bandgaps with suitable position of HOMO/LUMO energy levels, and high hole mobilities, leading to promising PCEs of 4.3%, 4.1% and 5.3%, respectively. Most significantly, the PTPTPTBT/PC71BM-based device with inverted architecture achieved an impressively high PCE of 5.9%. This value is among the highest performance from the inverted solar cells incorporating a donor-acceptor low bandgap polymer.
URI: http://140.113.39.130/cdrfb3/record/nctu/#GT079725826
http://hdl.handle.net/11536/45230
Appears in Collections:Thesis