Exploring
a Fused 2‑(Thiophen-2-yl)thieno[3,2‑<i>b</i>]thiophene (T-TT) Building Block to Construct n‑Type Polymer
for High-Performance All-Polymer Solar Cells
Ning An
Huijuan Ran
Yanfang Geng
Qingdao Zeng
Jianyong Hu
Jing Yang
Yanming Sun
Xiaochen Wang
Erjun Zhou
10.1021/acsami.9b12814.s001
https://acs.figshare.com/articles/journal_contribution/Exploring_a_Fused_2_Thiophen-2-yl_thieno_3_2_i_b_i_thiophene_T-TT_Building_Block_to_Construct_n_Type_Polymer_for_High-Performance_All-Polymer_Solar_Cells/10072658
In the field of all-polymer
solar cells, exploring new electron-donating units (D) to match with
electron-accepting units (A) is an important subject to promote the
performance of D–A-type polymer acceptors. Herein, we developed
a fused D unit 2-(thiophen-2-yl)thieno[3,2-<i>b</i>]thiophene
(T-TT) derivated from the famous 2-(2-(thiophen-2-yl)vinyl)thiophene
(TVT) unit. With classical naphthalene diimide (NDI) as A unit, the
new D–A polymer <b>PNDI–T-TT</b> exhibits enhanced
absorption coefficient, electron mobility, and miscibility with donor
polymer in comparison with the analogous <b>PNDI–TVT</b> polymer. These advantages can be attributed to the enlarged conjugation
and reduced rotamers due to the fused T-TT unit, leading to a stronger
intermolecular interaction. When blending with the donor polymer PBDB-T,
both NDI-based polymers can form better interpenetrating nanostructures
than the corresponding blend films with the donor polymer J71. Finally,
PBDB-T/<b>PNDI–T-TT</b> device achieves a power conversion
efficiency of 6.1%, which is much higher than that of PBDB-T/<b>PNDI–TVT</b> device (4.24%). These results demonstrate
that n-type polymer based on fused T-TT unit can ameliorate the absorption
coefficient, molecular aggregation, and charge-carrier mobility and
consequently achieve an improved photovoltaic performance in comparison
with the classic TVT unit.
2019-10-29 19:13:21
donor polymer J 71.
absorption coefficient
power conversion efficiency
-2-yl
TVT
PNDI
High-Performance All-Polymer Solar Cells
NDI
T-TT unit
donor polymer PBDB-T