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Title: Fine Tuning of Open-Circuit Voltage by Chlorination in Thieno[3,4- b ]thiophene–Benzodithiophene Terpolymers toward Enhanced Solar Energy Conversion

Abstract

A new family of thieno[3,4-b]thiophene benzodithiophene terpolymers (PBTClx) have been designed and synthesized, in which the chlorine/fluorine content has been adjusted and optimized. As the content of chlorine is increased in polymers, the twist angle between the donor and acceptor is increased, which leads to a diminishment in the planarity and conjugation. As a result, the UV vis absorption is continuous blue-shifted, and the band gap increases from 1.57 to 2.04 eV when the chlorinated moieties increased from 0 to 100%. The highest occupied molecular orbital (HOMO) levels of those polymers are decreased by increasing the content of chlorinated moiety, which opens a window to constantly modify the V-oc values and eventually meets a balance point for optimized solar energy conversion. The highest power conversion efficiency of 8.31% is obtained by using PBTCl25 as the donor and PC71BM as the acceptor in polymer solar cells (PSCs), in which the Voc increased from 0.79 to 0.82 V after 25% chlorinated monomer involved in copolymerization. Herein, the chlorine replacement could be a good method to further pump the solar conversion by increasing the open circuit voltage without reducing other factors of the polymer solar cells.

Authors:
; ; ; ; ; ; ORCiD logo; ORCiD logo [1]; ORCiD logo
  1. Materials Science Division, Argonne National Laboratory, 9700 Cass Avenue, Lemont, Illinois 60439, United States; Institute for Molecular Engineering, The University of Chicago, 5640 South Ellis Avenue, Chicago, Illinois 60637, United States
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
South University of Science and Technology of China (SUSTC); National Basic Research Program of China; National Natural Science Foundation of China (NNSFC); USDOE Office of Science - Office of Basic Energy Sciences - Materials Sciences and Engineering Division; USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1376711
DOE Contract Number:
AC02-06CH11357
Resource Type:
Journal Article
Resource Relation:
Journal Name: Macromolecules; Journal Volume: 50; Journal Issue: 13
Country of Publication:
United States
Language:
English

Citation Formats

Qu, Shiwei, Wang, Huan, Mo, Daize, Chao, Pengjie, Yang, Zhen, Li, Longji, Tian, Leilei, Chen, Wei, and He, Feng. Fine Tuning of Open-Circuit Voltage by Chlorination in Thieno[3,4- b ]thiophene–Benzodithiophene Terpolymers toward Enhanced Solar Energy Conversion. United States: N. p., 2017. Web. doi:10.1021/acs.macromol.7b00785.
Qu, Shiwei, Wang, Huan, Mo, Daize, Chao, Pengjie, Yang, Zhen, Li, Longji, Tian, Leilei, Chen, Wei, & He, Feng. Fine Tuning of Open-Circuit Voltage by Chlorination in Thieno[3,4- b ]thiophene–Benzodithiophene Terpolymers toward Enhanced Solar Energy Conversion. United States. doi:10.1021/acs.macromol.7b00785.
Qu, Shiwei, Wang, Huan, Mo, Daize, Chao, Pengjie, Yang, Zhen, Li, Longji, Tian, Leilei, Chen, Wei, and He, Feng. Thu . "Fine Tuning of Open-Circuit Voltage by Chlorination in Thieno[3,4- b ]thiophene–Benzodithiophene Terpolymers toward Enhanced Solar Energy Conversion". United States. doi:10.1021/acs.macromol.7b00785.
@article{osti_1376711,
title = {Fine Tuning of Open-Circuit Voltage by Chlorination in Thieno[3,4- b ]thiophene–Benzodithiophene Terpolymers toward Enhanced Solar Energy Conversion},
author = {Qu, Shiwei and Wang, Huan and Mo, Daize and Chao, Pengjie and Yang, Zhen and Li, Longji and Tian, Leilei and Chen, Wei and He, Feng},
abstractNote = {A new family of thieno[3,4-b]thiophene benzodithiophene terpolymers (PBTClx) have been designed and synthesized, in which the chlorine/fluorine content has been adjusted and optimized. As the content of chlorine is increased in polymers, the twist angle between the donor and acceptor is increased, which leads to a diminishment in the planarity and conjugation. As a result, the UV vis absorption is continuous blue-shifted, and the band gap increases from 1.57 to 2.04 eV when the chlorinated moieties increased from 0 to 100%. The highest occupied molecular orbital (HOMO) levels of those polymers are decreased by increasing the content of chlorinated moiety, which opens a window to constantly modify the V-oc values and eventually meets a balance point for optimized solar energy conversion. The highest power conversion efficiency of 8.31% is obtained by using PBTCl25 as the donor and PC71BM as the acceptor in polymer solar cells (PSCs), in which the Voc increased from 0.79 to 0.82 V after 25% chlorinated monomer involved in copolymerization. Herein, the chlorine replacement could be a good method to further pump the solar conversion by increasing the open circuit voltage without reducing other factors of the polymer solar cells.},
doi = {10.1021/acs.macromol.7b00785},
journal = {Macromolecules},
number = 13,
volume = 50,
place = {United States},
year = {Thu Jun 22 00:00:00 EDT 2017},
month = {Thu Jun 22 00:00:00 EDT 2017}
}