以蒽及噻吩熔合之五環平面分子所形成共軛高分子與小分子之合成及其在有機場效電晶體與有機太陽能電池之應用

Abstract

本研究合成出不含結構異構物彎曲型 anthradithiophene (ADT) 五環平面單體，四個辛烷基側鏈被導入至 ADT以增加溶解度。ADT單體與六個受體單元進行共聚: thienopyrrolodione (TPD)、difluorobenzothiadiazole (FBT)、dithienylbenzothiadiazole (DTBT)、dithienyldifluorobenzothiadiazole (DTFBT)、dithienodiketopyrrolopyrrole (DPP)、diphenyldiketopyrrolopyrrole (phDPP) 以得到六個donor-acceptor (D-A) 類型的交替高分子PADTTPD、PADTFBT、PADTDTBT、PADTDTFBT、PADTDPP、PADTphDPP。這些高分子被用來製作成有機薄膜電晶體 (OTFT) 與有機太陽能電池 (OPV) 元件。 在此六個 D-A類型之共聚高分子中，PADTDPP表現出最高之電洞遷移率 7.3 × 10-2 cm2 V-1 s-1，且其 OPV元件轉換效率可以達到 4.24 %。其中以 BT為基礎的共聚高分子裡，則以 PADTDTFBT表現最佳，為 1.29 × 10-2 cm2 V-1 s-1。 ADT單體也與雙噻吩 (2T) 共聚合為PADT2T，其 OTFT 表現也達到高遷移率 7.9 × 10-2 cm2 V-1 s-1，在以鑽石膜對氧化矽進行表面處理後遷移率更進一步達到 0.22 cm2 V-1 s-1。 ADT單體更進一步與單官能基修飾的 DPP、BT反應，得到兩共軛小分子 ADTDPP2、ADTBT2。其 OTFT 元件遷移率分別為 4.0 × 10-2 cm2 V-1 s-1 及 6.6 × 10-4 cm2 V-1 s-1 此值與其各相對應之高分子相去不遠。

In this study, we synthesized an angular-shaped anthradithiophene (ADT) pentacyclic planar monomer unit which contains no structure isomers. Four octyl side chains were introduced to ADT unit to increase the solubility. The ADT monomer was copolymerized with six different acceptor units, i.e. thienopyrrolodione (TPD), difluorobenzothiadiazole (FBT), dithienylbenzothiadiazole (DTBT), dithienyldifluorobenzothiadiazole (DTFBT), dithienodiketopyrrolopyrrole (DPP), and diphenyldiketopyrrolopyrrole (phDPP) to obtain six donor-acceptor (D-A) type alternating copolymers: PADTTPD, PADTFBT, PADTDTBT, PADTDTFBT, PADTDPP, and PADTphDPP. The obtained polymers were used to fabricate the organic thin-film transistors (OTFTs) and organic photovoltaics (OPVs). Among these six D-A type copolymers, PADTDPP showed the highest mobility of 7.3 × 10-2 cm2 V-1 s-1, and its OPV device reached a PCE value of 4.24 %. In the benzothiadiazole (BT) based copolymers, PADTDTFBT revealed the highest mobility of 1.29 × 10-2 cm2 V-1 s-1. The ADT monomer also copolymerized with bithiophene unit (2T) to form the alternating copolymer (PADT2T). The OTFT device based on PADT2T gave a high mobility of 7.9 × 10-2 cm2 V-1 s-1, this value was further optimized to 0.22 cm2 V-1 s-1 by surface treatment of silicon oxide with diamond film. The ADT monomer was further reacted with mono-functionalized DPP and BT unit to obtain two conjugated small molecules ADTDPP2 and ADTBT2. The OTFT devices based on ADTDPP2 and ADTBT2 revealed mobilities of 4.0 × 10-2 cm2 V-1 s-1 and 6.6 × 10-4 cm2 V-1 s-1, respectively, which were not far from their corresponding polymers.