Boosting
Up Performance of Inverted Photovoltaic Cells from Bis(alkylthien-2-yl)dithieno[2,3‑<i>d</i>:2′,3′‑<i>d</i>′]benzo[1,2‑<i>b</i>:4′,5′‑<i>b</i>′]di
thiophene-Based Copolymers by Advantageous Vertical Phase Separation
Pengzhi Guo
Guoping Luo
Qiang Su
Jianfeng Li
Peng Zhang
Junfeng Tong
Chunyan Yang
Yangjun Xia
Hongbin Wu
10.1021/acsami.6b15436.s001
https://acs.figshare.com/articles/journal_contribution/Boosting_Up_Performance_of_Inverted_Photovoltaic_Cells_from_Bis_alkylthien-2-yl_dithieno_2_3_i_d_i_2_3_i_d_i_benzo_1_2_i_b_i_4_5_i_b_i_di_thiophene-Based_Copolymers_by_Advantageous_Vertical_Phase_Separation/4765690
The
photovoltaic cells (PVCs) from conjugated copolymers of PDTBDT-BT
and PDTBDT-FBT with 5,10-bis(4,5-didecylthien-2-yl)dithieno[2,3-<i>d</i>:2′,3′-<i>d</i>′]benzo[1,2-<i>b</i>:4,5-<i>b</i>′]dithiophene as electron
donor moieties and benzothiadiazole and/or 5,6-difluorobenzothiadiazole
as electron acceptor moieties are optimized by employing alcohol-soluble
PFN (poly(9,9-bis(3′-(<i>N</i>,<i>N</i>-dimethylamino)propyl)-2,7-fluorene)-<i>alt</i>-2,7-(9,9-dioctylfluorene))
as cathode modification interlayer. The power conversion efficiencies
(PCEs) of inverted PVCs (<i>i-</i>PVCs) from PDTBDT-BT and
PDTBDT-FBT with devices configuration as ITO/PFN/active layer/MoO<sub>3</sub>/Ag are increased from 4.97% to 8.54% and 5.92% to 8.74%,
in contrast to those for the regular PVCs (<i>r-</i>PVCs)
with devices configuration as ITO/PEDOT:PSS/active layer/Ca/Al under
100 mW/cm<sup>2</sup> AM 1.5 illumination. The optical modeling calculations
and X-ray photoelectron spectroscopy (XPS) investigations reveal that
the <i>r-</i>PVCs and <i>i-</i>PVCs from the copolymers
exhibit similar light harvesting characteristics, and the enhancements
of the PCEs of the <i>i-</i>PVCs from the copolymers are
mainly contributed to the favorable vertical phase separation as the
strongly polymer-enriched top surface layers and slightly PC<sub>71</sub>BM (phenyl-C<sub>71</sub>-butyric acid methyl ester)-enriched bottom
surface layers are correspondingly connected to the anodes and cathodes
of the <i>i-</i>PVCs, while they are opposite in the <i>r-</i>PVCs. As we known, it is the first time to experimentally
verify that the <i>i-</i>PVCs with alcohol-soluble conjugated
polymers cathode modification layers enjoy favorable vertical phase
separation.
2017-03-09 00:00:00
XPS
PDTBDT-FBT
devices configuration
Inverted Photovoltaic Cells
power conversion efficiencies
PCE
polymers cathode modification layers
light harvesting characteristics
PC 71 BM
Advantageous Vertical Phase Separation
PDTBDT-BT
electron acceptor moieties
phase separation
ITO
electron donor moieties
cathode modification interlayer
AM
X-ray photoelectron spectroscopy
PFN