CC BY-NC-ND 4.0 · Organic Materials 2021; 03(02): 204-213
DOI: 10.1055/a-1472-7109
Focus Issue: Peter Bäuerle 65th Birthday
Original Article

Influence of the Location of Electron-Donating 3,4-Ethylenedioxythiophene (EDOT) Moiety in the A–π–D–π–A Type Conjugated Molecules on the Optoelectronic Properties and Photovoltaic Performances

Lilei Wang
a   Printable Electronics Research Center, Suzhou Institute of Nano-Tech and Nano-Bionics (SINANO), Chinese Academy of Sciences, 398 Ruo Shui Road, SEID SIP, Suzhou, Jiangsu, 215123, P. R. China
b   Department of Chemistry, Shanghai Key Laboratory of Green Chemistry and Chemical, East China Normal University, 3663 North Zhongshan Road, Shanghai 200062, P. R. China
,
Ying Zhang
c   College of Chemistry, Beijing Normal University, 19 XinJieKouWai Street, HaiDian District Beijing 100875, P. R. China
,
Xiang Guan
a   Printable Electronics Research Center, Suzhou Institute of Nano-Tech and Nano-Bionics (SINANO), Chinese Academy of Sciences, 398 Ruo Shui Road, SEID SIP, Suzhou, Jiangsu, 215123, P. R. China
,
Wei Gao
a   Printable Electronics Research Center, Suzhou Institute of Nano-Tech and Nano-Bionics (SINANO), Chinese Academy of Sciences, 398 Ruo Shui Road, SEID SIP, Suzhou, Jiangsu, 215123, P. R. China
,
Yi Lin
d   Department of Chemistry, Xi'an Jiaotong Liverpool University, 111 Ren Ai Road, SEID SIP, Suzhou, Jiangsu, 215123, P. R. China
,
Qun Luo
a   Printable Electronics Research Center, Suzhou Institute of Nano-Tech and Nano-Bionics (SINANO), Chinese Academy of Sciences, 398 Ruo Shui Road, SEID SIP, Suzhou, Jiangsu, 215123, P. R. China
,
Hongwei Tan
c   College of Chemistry, Beijing Normal University, 19 XinJieKouWai Street, HaiDian District Beijing 100875, P. R. China
,
b   Department of Chemistry, Shanghai Key Laboratory of Green Chemistry and Chemical, East China Normal University, 3663 North Zhongshan Road, Shanghai 200062, P. R. China
,
a   Printable Electronics Research Center, Suzhou Institute of Nano-Tech and Nano-Bionics (SINANO), Chinese Academy of Sciences, 398 Ruo Shui Road, SEID SIP, Suzhou, Jiangsu, 215123, P. R. China
› Author Affiliations
Funding Information Financial support for this project was provided by the National Natural Science Foundation of China (22075315) and by Xi'an Jiaotong-Liverpool University Research Development Fund (RDF-14-02-46).


Abstract

A–π–D–π–A type conjugated small molecules play an indispensable role in organic photovoltaics. Understanding the relationship between the molecular structure and performance is a fundamental question for the further rational design of high-performance organic materials. To red-shift the absorption spectrum of benzo[1,2-b:4,5-b']dithiophene (BDT) based A–π–D–π–A type compounds, an electron-donating 3,4-ethylenedioxythiophene (EDOT) moiety was introduced into the π-conjugation bridge unit. Two new compounds with EDOT next to the central BDT core (COOP-2HT-EDOT-BDT) or next to the terminal electron acceptor unit (COOP-EDOT-2HT-BDT) were synthesized and characterized. The compound COOP-2HT-EDOT-BDT showed higher molar extinction coefficient (εabs max = 1.06 × 105 L mol−1 cm−1), lower optical band gap (E g = 1.56 eV) and high HOMO energy level (E HOMO = −5.08 eV) than COOP-EDOT-2HT-BDTabs max = 0.96 × 105 L mol−1 cm−1, E g = 1.71 eV, E HOMO = −5.26 eV), which is attributed to the intensive interaction between the EDOT unit and the HOMO orbital, as confirmed by the theoretical calculation results. However, the higher power conversion efficiency of 3.58% was achieved for the COOP-EDOT-2HT-BDT:PC61BM-based solar cells, demonstrating that the electron-donating EDOT unit adjacent to the electron-withdrawing end-capped group (COOP) is a better way to achieve high-performance photovoltaic materials.

Supporting Information

Supporting information for this article is available online at https://doi.org/10.1055/a-1472-7109.


Dedication to Prof. Peter Bäuerle on the occasion of his 65th birthday.


Supporting Information



Publication History

Received: 11 February 2021

Accepted: 16 March 2021

Accepted Manuscript online:
01 April 2021

Article published online:
26 May 2021

© 2021. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/)

Georg Thieme Verlag KG
Rüdigerstraße 14, 70469 Stuttgart, Germany