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Indexed by:期刊论文

Date of Publication:2017-05-01

Journal:DYES AND PIGMENTS

Included Journals:SCIE、EI

Volume:140

Page Number:203-211

ISSN No.:0143-7208

Key Words:Benzothiadiazole; Ethynyl; Carbazole; Triphenylamine; Photovoltaic performance; Bulk heterojunction

Abstract:Two novel D-pi-A-pi-D-typed dioctyloxy-benzothiadiazole (DOBT)-based small molecules (SMs), TPAEDOBT and CZEDOBT, were designed and synthesized, consisting of ethynyl as pi-linkage, besides, incorporating triphenylamine (TPA) and alkylated-carbazole (Cz) as terminal electron-donating units respectively. Single-bond compounds, TPADOBT and CZDOBT, were designed as references to fully investigate their photovoltaic (PV) performance of solution-processed devices. As expected, the PV properties were finely tuned via molecular design with ethynyl-linker and terminal electron-donating units. Among them, the best power conversion efficiency (PCE) of 3.21% was obtained for TPAEDOBT-based device due to triple-bond effect and high hole-mobility. Most importantly, a remarkably increased open-circuit voltage (Voc) of 1.06 V was achieved for CZEDOBT-based device due to synergistic effect of ethynyl-linker with electron-withdrawing character and Cz unit with the relatively weakened electron donating ability, which is among the earliest report for DOBT-Cz based SMs with high Voc so far. These results provide an important guide for rational design of novel SMs PV materials. (C) 2017 Elsevier Ltd. All rights reserved.